diff --git a/assignment-client/src/AssignmentClient.cpp b/assignment-client/src/AssignmentClient.cpp
index 4fc8975262..800f00b352 100644
--- a/assignment-client/src/AssignmentClient.cpp
+++ b/assignment-client/src/AssignmentClient.cpp
@@ -91,7 +91,7 @@ AssignmentClient::AssignmentClient(Assignment::Type requestAssignmentType, QStri
     // check for a wallet UUID on the command line or in the config
     // this would represent where the user running AC wants funds sent to
     if (!walletUUID.isNull()) {
-        qCDebug(assigmnentclient) << "The destination wallet UUID for credits is" << uuidStringWithoutCurlyBraces(walletUUID);
+        qCDebug(assignment_client) << "The destination wallet UUID for credits is" << uuidStringWithoutCurlyBraces(walletUUID);
         _requestAssignment.setWalletUUID(walletUUID);
     }
 
@@ -102,16 +102,16 @@ AssignmentClient::AssignmentClient(Assignment::Type requestAssignmentType, QStri
     }
 
     _assignmentServerSocket = HifiSockAddr(_assignmentServerHostname, assignmentServerPort, true);
-    _assignmentServerSocket.setObjectName("AssigmentServer");
+    _assignmentServerSocket.setObjectName("AssignmentServer");
     nodeList->setAssignmentServerSocket(_assignmentServerSocket);
 
-    qCDebug(assigmnentclient) << "Assignment server socket is" << _assignmentServerSocket;
+    qCDebug(assignment_client) << "Assignment server socket is" << _assignmentServerSocket;
 
     // call a timer function every ASSIGNMENT_REQUEST_INTERVAL_MSECS to ask for assignment, if required
-    qCDebug(assigmnentclient) << "Waiting for assignment -" << _requestAssignment;
+    qCDebug(assignment_client) << "Waiting for assignment -" << _requestAssignment;
 
     if (_assignmentServerHostname != "localhost") {
-        qCDebug(assigmnentclient) << "- will attempt to connect to domain-server on" << _assignmentServerSocket.getPort();
+        qCDebug(assignment_client) << "- will attempt to connect to domain-server on" << _assignmentServerSocket.getPort();
     }
 
     connect(&_requestTimer, SIGNAL(timeout()), SLOT(sendAssignmentRequest()));
@@ -129,7 +129,7 @@ AssignmentClient::AssignmentClient(Assignment::Type requestAssignmentType, QStri
         _assignmentClientMonitorSocket = HifiSockAddr(DEFAULT_ASSIGNMENT_CLIENT_MONITOR_HOSTNAME, assignmentMonitorPort);
         _assignmentClientMonitorSocket.setObjectName("AssignmentClientMonitor");
 
-        qCDebug(assigmnentclient) << "Assignment-client monitor socket is" << _assignmentClientMonitorSocket;
+        qCDebug(assignment_client) << "Assignment-client monitor socket is" << _assignmentClientMonitorSocket;
 
         // Hook up a timer to send this child's status to the Monitor once per second
         setUpStatusToMonitor();
@@ -140,7 +140,7 @@ AssignmentClient::AssignmentClient(Assignment::Type requestAssignmentType, QStri
 }
 
 void AssignmentClient::stopAssignmentClient() {
-    qCDebug(assigmnentclient) << "Forced stop of assignment-client.";
+    qCDebug(assignment_client) << "Forced stop of assignment-client.";
 
     _requestTimer.stop();
     _statsTimerACM.stop();
@@ -218,14 +218,14 @@ void AssignmentClient::sendAssignmentRequest() {
             quint16 localAssignmentServerPort;
             if (nodeList->getLocalServerPortFromSharedMemory(DOMAIN_SERVER_LOCAL_PORT_SMEM_KEY, localAssignmentServerPort)) {
                 if (localAssignmentServerPort != _assignmentServerSocket.getPort()) {
-                    qCDebug(assigmnentclient) << "Port for local assignment server read from shared memory is"
+                    qCDebug(assignment_client) << "Port for local assignment server read from shared memory is"
                         << localAssignmentServerPort;
 
                     _assignmentServerSocket.setPort(localAssignmentServerPort);
                     nodeList->setAssignmentServerSocket(_assignmentServerSocket);
                 }
             } else {
-                qCWarning(assigmnentclient) << "Failed to read local assignment server port from shared memory"
+                qCWarning(assignment_client) << "Failed to read local assignment server port from shared memory"
                     << "- will send assignment request to previous assignment server socket.";
             }
         }
@@ -235,10 +235,10 @@ void AssignmentClient::sendAssignmentRequest() {
 }
 
 void AssignmentClient::handleCreateAssignmentPacket(QSharedPointer<ReceivedMessage> message) {
-    qCDebug(assigmnentclient) << "Received a PacketType::CreateAssignment - attempting to unpack.";
+    qCDebug(assignment_client) << "Received a PacketType::CreateAssignment - attempting to unpack.";
 
     if (_currentAssignment) {
-        qCWarning(assigmnentclient) << "Received a PacketType::CreateAssignment while still running an active assignment. Ignoring.";
+        qCWarning(assignment_client) << "Received a PacketType::CreateAssignment while still running an active assignment. Ignoring.";
         return;
     }
 
@@ -246,7 +246,7 @@ void AssignmentClient::handleCreateAssignmentPacket(QSharedPointer<ReceivedMessa
     _currentAssignment = AssignmentFactory::unpackAssignment(*message);
 
     if (_currentAssignment && !_isAssigned) {
-        qDebug(assigmnentclient) << "Received an assignment -" << *_currentAssignment;
+        qDebug(assignment_client) << "Received an assignment -" << *_currentAssignment;
         _isAssigned = true;
 
         auto nodeList = DependencyManager::get<NodeList>();
@@ -256,7 +256,7 @@ void AssignmentClient::handleCreateAssignmentPacket(QSharedPointer<ReceivedMessa
         nodeList->getDomainHandler().setSockAddr(message->getSenderSockAddr(), _assignmentServerHostname);
         nodeList->getDomainHandler().setAssignmentUUID(_currentAssignment->getUUID());
 
-        qCDebug(assigmnentclient) << "Destination IP for assignment is" << nodeList->getDomainHandler().getIP().toString();
+        qCDebug(assignment_client) << "Destination IP for assignment is" << nodeList->getDomainHandler().getIP().toString();
 
         // start the deployed assignment
         QThread* workerThread = new QThread;
@@ -284,7 +284,7 @@ void AssignmentClient::handleCreateAssignmentPacket(QSharedPointer<ReceivedMessa
         // Starts an event loop, and emits workerThread->started()
         workerThread->start();
     } else {
-        qCWarning(assigmnentclient) << "Received an assignment that could not be unpacked. Re-requesting.";
+        qCWarning(assignment_client) << "Received an assignment that could not be unpacked. Re-requesting.";
     }
 }
 
@@ -294,10 +294,10 @@ void AssignmentClient::handleStopNodePacket(QSharedPointer<ReceivedMessage> mess
     if (senderSockAddr.getAddress() == QHostAddress::LocalHost ||
         senderSockAddr.getAddress() == QHostAddress::LocalHostIPv6) {
         
-        qCDebug(assigmnentclient) << "AssignmentClientMonitor at" << senderSockAddr << "requested stop via PacketType::StopNode.";
+        qCDebug(assignment_client) << "AssignmentClientMonitor at" << senderSockAddr << "requested stop via PacketType::StopNode.";
         QCoreApplication::quit();
     } else {
-        qCWarning(assigmnentclient) << "Got a stop packet from other than localhost.";
+        qCWarning(assignment_client) << "Got a stop packet from other than localhost.";
     }
 }
 
@@ -317,7 +317,7 @@ void AssignmentClient::handleAuthenticationRequest() {
         // ask the account manager to log us in from the env variables
         accountManager->requestAccessToken(username, password);
     } else {
-        qCWarning(assigmnentclient) << "Authentication was requested against" << qPrintable(accountManager->getAuthURL().toString())
+        qCWarning(assignment_client) << "Authentication was requested against" << qPrintable(accountManager->getAuthURL().toString())
             << "but both or one of" << qPrintable(DATA_SERVER_USERNAME_ENV)
             << "/" << qPrintable(DATA_SERVER_PASSWORD_ENV) << "are not set. Unable to authenticate.";
 
@@ -335,7 +335,7 @@ void AssignmentClient::assignmentCompleted() {
     // reset the logging target to the the CHILD_TARGET_NAME
     LogHandler::getInstance().setTargetName(ASSIGNMENT_CLIENT_TARGET_NAME);
 
-    qCDebug(assigmnentclient) << "Assignment finished or never started - waiting for new assignment.";
+    qCDebug(assignment_client) << "Assignment finished or never started - waiting for new assignment.";
 
     auto nodeList = DependencyManager::get<NodeList>();
 
diff --git a/assignment-client/src/AssignmentClientLogging.cpp b/assignment-client/src/AssignmentClientLogging.cpp
index 890187ecaa..9110dccc5f 100644
--- a/assignment-client/src/AssignmentClientLogging.cpp
+++ b/assignment-client/src/AssignmentClientLogging.cpp
@@ -11,4 +11,4 @@
 
 #include "AssignmentClientLogging.h"
 
-Q_LOGGING_CATEGORY(assigmnentclient, "hifi.assignment-client")
\ No newline at end of file
+Q_LOGGING_CATEGORY(assignment_client, "hifi.assignment-client")
\ No newline at end of file
diff --git a/assignment-client/src/AssignmentClientLogging.h b/assignment-client/src/AssignmentClientLogging.h
index d6b5ee90e0..88e2add017 100644
--- a/assignment-client/src/AssignmentClientLogging.h
+++ b/assignment-client/src/AssignmentClientLogging.h
@@ -14,6 +14,6 @@
 
 #include <QLoggingCategory>
 
-Q_DECLARE_LOGGING_CATEGORY(assigmnentclient)
+Q_DECLARE_LOGGING_CATEGORY(assignment_client)
 
 #endif // hifi_AssignmentClientLogging_h
\ No newline at end of file
diff --git a/assignment-client/src/audio/AudioMixer.cpp b/assignment-client/src/audio/AudioMixer.cpp
index 2d2f9c267e..ccd80a4a11 100644
--- a/assignment-client/src/audio/AudioMixer.cpp
+++ b/assignment-client/src/audio/AudioMixer.cpp
@@ -269,19 +269,17 @@ void AudioMixer::addStreamToMixForListeningNodeWithStream(AudioMixerClientData&
         bool forceSilentBlock = true;
 
         if (!streamToAdd.getLastPopOutput().isNull()) {
+            bool isInjector = dynamic_cast<const InjectedAudioStream*>(&streamToAdd);
 
-            // reptition with fade is enabled, and we do have a valid previous frame to repeat
-            // so we mix the previously-mixed block
-
-            // this is preferable to not mixing it at all to avoid the harsh jump to silence
+            // in an injector, just go silent - the injector has likely ended
+            // in other inputs (microphone, &c.), repeat with fade to avoid the harsh jump to silence
 
             // we'll repeat the last block until it has a block to mix
             // and we'll gradually fade that repeated block into silence.
 
             // calculate its fade factor, which depends on how many times it's already been repeated.
-
             repeatedFrameFadeFactor = calculateRepeatedFrameFadeFactor(streamToAdd.getConsecutiveNotMixedCount() - 1);
-            if (repeatedFrameFadeFactor > 0.0f) {
+            if (!isInjector && repeatedFrameFadeFactor > 0.0f) {
                 // apply the repeatedFrameFadeFactor to the gain
                 gain *= repeatedFrameFadeFactor;
 
diff --git a/cmake/externals/wasapi/CMakeLists.txt b/cmake/externals/wasapi/CMakeLists.txt
index 019920df77..8ec327600f 100644
--- a/cmake/externals/wasapi/CMakeLists.txt
+++ b/cmake/externals/wasapi/CMakeLists.txt
@@ -6,8 +6,8 @@ if (WIN32)
   include(ExternalProject)
   ExternalProject_Add(
     ${EXTERNAL_NAME}
-    URL http://hifi-public.s3.amazonaws.com/dependencies/qtaudio_wasapi.zip
-    URL_MD5 11c8a7728d6eda7223df800e10b70723
+    URL http://hifi-public.s3.amazonaws.com/dependencies/qtaudio_wasapi2.zip
+    URL_MD5 272b27bd6c211c45c0c23d4701b63b5e
     CONFIGURE_COMMAND ""
     BUILD_COMMAND ""
     INSTALL_COMMAND ""
diff --git a/cmake/macros/PackageLibrariesForDeployment.cmake b/cmake/macros/PackageLibrariesForDeployment.cmake
index 7f826c1f8c..da0ee35769 100644
--- a/cmake/macros/PackageLibrariesForDeployment.cmake
+++ b/cmake/macros/PackageLibrariesForDeployment.cmake
@@ -49,6 +49,7 @@ macro(PACKAGE_LIBRARIES_FOR_DEPLOYMENT)
       TARGET ${TARGET_NAME}
       POST_BUILD
       COMMAND if exist ${QTAUDIO_PATH}/qtaudio_windows.dll ( ${CMAKE_COMMAND} -E remove ${QTAUDIO_PATH}/qtaudio_windows.dll && ${CMAKE_COMMAND} -E copy ${WASAPI_DLL_PATH}/qtaudio_wasapi.dll ${QTAUDIO_PATH} && ${CMAKE_COMMAND} -E copy ${WASAPI_DLL_PATH}/qtaudio_wasapi.pdb ${QTAUDIO_PATH} )
+      COMMAND if exist ${QTAUDIO_PATH}/qtaudio_windowsd.dll ( ${CMAKE_COMMAND} -E remove ${QTAUDIO_PATH}/qtaudio_windowsd.dll && ${CMAKE_COMMAND} -E copy ${WASAPI_DLL_PATH}/qtaudio_wasapid.dll ${QTAUDIO_PATH} && ${CMAKE_COMMAND} -E copy ${WASAPI_DLL_PATH}/qtaudio_wasapid.pdb ${QTAUDIO_PATH} )
     )
 
   endif ()
diff --git a/domain-server/src/DomainGatekeeper.cpp b/domain-server/src/DomainGatekeeper.cpp
index e33cbe1755..bf9d7d04a6 100644
--- a/domain-server/src/DomainGatekeeper.cpp
+++ b/domain-server/src/DomainGatekeeper.cpp
@@ -771,6 +771,21 @@ void DomainGatekeeper::getGroupMemberships(const QString& username) {
     // loop through the groups mentioned on the settings page and ask if this user is in each.  The replies
     // will be received asynchronously and permissions will be updated as the answers come in.
 
+    QJsonObject json;
+    QSet<QString> groupIDSet;
+    foreach (QUuid groupID, _server->_settingsManager.getGroupIDs() + _server->_settingsManager.getBlacklistGroupIDs()) {
+        groupIDSet += groupID.toString().mid(1,36);
+    }
+
+    if (groupIDSet.isEmpty()) {
+        // if no groups are in the permissions settings, don't ask who is in which groups.
+        return;
+    }
+
+    QJsonArray groupIDs = QJsonArray::fromStringList(groupIDSet.toList());
+    json["groups"] = groupIDs;
+
+
     // if we've already asked, wait for the answer before asking again
     QString lowerUsername = username.toLower();
     if (_inFlightGroupMembershipsRequests.contains(lowerUsername)) {
@@ -779,13 +794,6 @@ void DomainGatekeeper::getGroupMemberships(const QString& username) {
     }
     _inFlightGroupMembershipsRequests += lowerUsername;
 
-    QJsonObject json;
-    QSet<QString> groupIDSet;
-    foreach (QUuid groupID, _server->_settingsManager.getGroupIDs() + _server->_settingsManager.getBlacklistGroupIDs()) {
-        groupIDSet += groupID.toString().mid(1,36);
-    }
-    QJsonArray groupIDs = QJsonArray::fromStringList(groupIDSet.toList());
-    json["groups"] = groupIDs;
 
     JSONCallbackParameters callbackParams;
     callbackParams.jsonCallbackReceiver = this;
diff --git a/domain-server/src/DomainServer.cpp b/domain-server/src/DomainServer.cpp
index c1caa00d24..d7bcaa838e 100644
--- a/domain-server/src/DomainServer.cpp
+++ b/domain-server/src/DomainServer.cpp
@@ -1749,7 +1749,7 @@ bool DomainServer::handleHTTPRequest(HTTPConnection* connection, const QUrl& url
 
                 _ephemeralACScripts[scriptAssignment->getUUID()] = formData[0].second;
 
-                // add the script assigment to the assignment queue
+                // add the script assignment to the assignment queue
                 SharedAssignmentPointer sharedScriptedAssignment(scriptAssignment);
                 _unfulfilledAssignments.enqueue(sharedScriptedAssignment);
                 _allAssignments.insert(sharedScriptedAssignment->getUUID(), sharedScriptedAssignment);
diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index 4d4c63930e..6c80cfb9fd 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -68,6 +68,7 @@
 #include <InfoView.h>
 #include <input-plugins/InputPlugin.h>
 #include <controllers/UserInputMapper.h>
+#include <controllers/ScriptingInterface.h>
 #include <controllers/StateController.h>
 #include <UserActivityLoggerScriptingInterface.h>
 #include <LogHandler.h>
@@ -4918,6 +4919,10 @@ void Application::registerScriptEngineWithApplicationServices(ScriptEngine* scri
     scriptEngine->registerGlobalObject("Users", DependencyManager::get<UsersScriptingInterface>().data());
 
     scriptEngine->registerGlobalObject("Steam", new SteamScriptingInterface(scriptEngine));
+
+    auto scriptingInterface = DependencyManager::get<controller::ScriptingInterface>();
+    scriptEngine->registerGlobalObject("Controller", scriptingInterface.data());
+    UserInputMapper::registerControllerTypes(scriptEngine);
 }
 
 bool Application::canAcceptURL(const QString& urlString) const {
diff --git a/interface/src/Menu.cpp b/interface/src/Menu.cpp
index 3c1aa26a4a..74490b6dd1 100644
--- a/interface/src/Menu.cpp
+++ b/interface/src/Menu.cpp
@@ -355,7 +355,7 @@ Menu::Menu() {
     //const QString  = "1024 MB";
     //const QString  = "2048 MB";
 
-    // Developer > Render > Resolution
+    // Developer > Render > Maximum Texture Memory
     MenuWrapper* textureMenu = renderOptionsMenu->addMenu(MenuOption::RenderMaxTextureMemory);
     QActionGroup* textureGroup = new QActionGroup(textureMenu);
     textureGroup->setExclusive(true);
@@ -383,6 +383,43 @@ Menu::Menu() {
         gpu::Texture::setAllowedGPUMemoryUsage(newMaxTextureMemory);
     });
 
+#ifdef Q_OS_WIN
+    #define MIN_CORES_FOR_INCREMENTAL_TEXTURES 5
+    bool recommendedIncrementalTransfers = (QThread::idealThreadCount() >= MIN_CORES_FOR_INCREMENTAL_TEXTURES);
+    bool recommendedSparseTextures = recommendedIncrementalTransfers;
+
+    qDebug() << "[TEXTURE TRANSFER SUPPORT]"
+        << "\n\tidealThreadCount:" << QThread::idealThreadCount()
+        << "\n\tRECOMMENDED enableSparseTextures:" << recommendedSparseTextures
+        << "\n\tRECOMMENDED enableIncrementalTextures:" << recommendedIncrementalTransfers;
+
+    gpu::Texture::setEnableIncrementalTextureTransfers(recommendedIncrementalTransfers);
+    gpu::Texture::setEnableSparseTextures(recommendedSparseTextures);
+
+    // Developer > Render > Enable Dynamic Texture Management
+    {
+        auto action = addCheckableActionToQMenuAndActionHash(renderOptionsMenu, MenuOption::EnableDynamicTextureManagement, 0, recommendedSparseTextures);
+        connect(action, &QAction::triggered, [&](bool checked) {
+            qDebug() << "[TEXTURE TRANSFER SUPPORT] --- Enable Dynamic Texture Management menu option:" << checked;
+            gpu::Texture::setEnableSparseTextures(checked);
+        });
+    }
+
+    // Developer > Render > Enable Incremental Texture Transfer
+    {
+        auto action = addCheckableActionToQMenuAndActionHash(renderOptionsMenu, MenuOption::EnableIncrementalTextureTransfer, 0, recommendedIncrementalTransfers);
+        connect(action, &QAction::triggered, [&](bool checked) {
+            qDebug() << "[TEXTURE TRANSFER SUPPORT] --- Enable Incremental Texture Transfer menu option:" << checked;
+            gpu::Texture::setEnableIncrementalTextureTransfers(checked);
+        });
+    }
+
+#else
+    qDebug() << "[TEXTURE TRANSFER SUPPORT] Incremental Texture Transfer and Dynamic Texture Management not supported on this platform.";
+#endif
+
+
+
     // Developer > Render > LOD Tools
     addActionToQMenuAndActionHash(renderOptionsMenu, MenuOption::LodTools, 0, dialogsManager.data(), SLOT(lodTools()));
 
diff --git a/interface/src/Menu.h b/interface/src/Menu.h
index b25603caeb..95cd4c5aa6 100644
--- a/interface/src/Menu.h
+++ b/interface/src/Menu.h
@@ -98,6 +98,8 @@ namespace MenuOption {
     const QString EchoLocalAudio = "Echo Local Audio";
     const QString EchoServerAudio = "Echo Server Audio";
     const QString EnableCharacterController = "Enable avatar collisions";
+    const QString EnableIncrementalTextureTransfer = "Enable Incremental Texture Transfer";
+    const QString EnableDynamicTextureManagement = "Enable Dynamic Texture Management";
     const QString EnableInverseKinematics = "Enable Inverse Kinematics";
     const QString ExpandMyAvatarSimulateTiming = "Expand /myAvatar/simulation";
     const QString ExpandMyAvatarTiming = "Expand /myAvatar";
diff --git a/libraries/audio-client/src/AudioClient.h b/libraries/audio-client/src/AudioClient.h
index 97b5c14512..1b2a2da296 100644
--- a/libraries/audio-client/src/AudioClient.h
+++ b/libraries/audio-client/src/AudioClient.h
@@ -87,7 +87,7 @@ public:
         AudioOutputIODevice(MixedProcessedAudioStream& receivedAudioStream, AudioClient* audio) :
             _receivedAudioStream(receivedAudioStream), _audio(audio), _unfulfilledReads(0) {};
 
-        void start() { open(QIODevice::ReadOnly); }
+        void start() { open(QIODevice::ReadOnly | QIODevice::Unbuffered); }
         void stop() { close(); }
         qint64 readData(char * data, qint64 maxSize) override;
         qint64 writeData(const char * data, qint64 maxSize) override { return 0; }
@@ -167,7 +167,8 @@ public slots:
 
     int setOutputBufferSize(int numFrames, bool persist = true);
 
-    virtual bool outputLocalInjector(bool isStereo, AudioInjector* injector) override;
+    bool outputLocalInjector(bool isStereo, AudioInjector* injector) override;
+    bool shouldLoopbackInjectors() override { return _shouldEchoToServer; }
 
     bool switchInputToAudioDevice(const QString& inputDeviceName);
     bool switchOutputToAudioDevice(const QString& outputDeviceName);
diff --git a/libraries/audio/src/AbstractAudioInterface.h b/libraries/audio/src/AbstractAudioInterface.h
index 223421a7ab..ec96462e73 100644
--- a/libraries/audio/src/AbstractAudioInterface.h
+++ b/libraries/audio/src/AbstractAudioInterface.h
@@ -33,6 +33,7 @@ public:
 
 public slots:
     virtual bool outputLocalInjector(bool isStereo, AudioInjector* injector) = 0;
+    virtual bool shouldLoopbackInjectors() { return false; }
     
     virtual void setIsStereoInput(bool stereo) = 0;
 };
diff --git a/libraries/audio/src/AudioInjector.cpp b/libraries/audio/src/AudioInjector.cpp
index 43701a51d8..6f6534e2d2 100644
--- a/libraries/audio/src/AudioInjector.cpp
+++ b/libraries/audio/src/AudioInjector.cpp
@@ -211,6 +211,7 @@ int64_t AudioInjector::injectNextFrame() {
     }
 
     // if we haven't setup the packet to send then do so now
+    static int loopbackOptionOffset = -1;
     static int positionOptionOffset = -1;
     static int volumeOptionOffset = -1;
     static int audioDataOffset = -1;
@@ -260,10 +261,9 @@ int64_t AudioInjector::injectNextFrame() {
             // pack the stereo/mono type of the stream
             audioPacketStream << _options.stereo;
 
-            // pack the flag for loopback.  Now, we don't loopback
-            // and _always_ play locally, so loopbackFlag should be
-            // false always.
-            uchar loopbackFlag = (uchar)false;
+            // pack the flag for loopback, if requested
+            loopbackOptionOffset = _currentPacket->pos();
+            uchar loopbackFlag = (_localAudioInterface && _localAudioInterface->shouldLoopbackInjectors());
             audioPacketStream << loopbackFlag;
 
             // pack the position for injected audio
@@ -293,6 +293,7 @@ int64_t AudioInjector::injectNextFrame() {
             return NEXT_FRAME_DELTA_ERROR_OR_FINISHED;
         }
     }
+
     if (!_frameTimer->isValid()) {
         // in the case where we have been restarted, the frame timer will be invalid and we need to start it back over here
         _frameTimer->restart();
@@ -317,6 +318,9 @@ int64_t AudioInjector::injectNextFrame() {
     // pack the sequence number
     _currentPacket->writePrimitive(_outgoingSequenceNumber);
 
+    _currentPacket->seek(loopbackOptionOffset);
+    _currentPacket->writePrimitive((uchar)(_localAudioInterface && _localAudioInterface->shouldLoopbackInjectors()));
+
     _currentPacket->seek(positionOptionOffset);
     _currentPacket->writePrimitive(_options.position);
     _currentPacket->writePrimitive(_options.orientation);
diff --git a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h
index ef15861843..74f8cdbc10 100644
--- a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h
+++ b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h
@@ -8,6 +8,7 @@
 #pragma once
 
 #include "DisplayPlugin.h"
+#include <gl/Config.h>
 
 #include <condition_variable>
 #include <memory>
@@ -18,7 +19,6 @@
 
 #include <GLMHelpers.h>
 #include <SimpleMovingAverage.h>
-#include <gl/GLEscrow.h>
 #include <shared/RateCounter.h>
 
 namespace gpu {
@@ -35,7 +35,6 @@ protected:
     using Mutex = std::mutex;
     using Lock = std::unique_lock<Mutex>;
     using Condition = std::condition_variable;
-    using TextureEscrow = GLEscrow<gpu::TexturePointer>;
 public:
     // These must be final to ensure proper ordering of operations 
     // between the main thread and the presentation thread
diff --git a/libraries/gl/src/gl/GLWidget.cpp b/libraries/gl/src/gl/GLWidget.cpp
index f2b823a65e..23bdcff640 100644
--- a/libraries/gl/src/gl/GLWidget.cpp
+++ b/libraries/gl/src/gl/GLWidget.cpp
@@ -67,8 +67,8 @@ void GLWidget::createContext() {
     _context = new gl::Context();
     _context->setWindow(windowHandle());
     _context->create();
-    _context->clear();
     _context->makeCurrent();
+    _context->clear();
 }
 
 bool GLWidget::makeCurrent() {
diff --git a/libraries/gl/src/gl/OffscreenQmlSurface.cpp b/libraries/gl/src/gl/OffscreenQmlSurface.cpp
index 74cdb78b46..164abbd671 100644
--- a/libraries/gl/src/gl/OffscreenQmlSurface.cpp
+++ b/libraries/gl/src/gl/OffscreenQmlSurface.cpp
@@ -6,7 +6,11 @@
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
 #include "OffscreenQmlSurface.h"
-#include "OglplusHelpers.h"
+#include "Config.h"
+
+#include <queue>
+#include <set>
+#include <map>
 
 #include <QtWidgets/QWidget>
 #include <QtQml/QtQml>
@@ -116,6 +120,108 @@ static const QEvent::Type RENDER = QEvent::Type(QEvent::User + 2);
 static const QEvent::Type RESIZE = QEvent::Type(QEvent::User + 3);
 static const QEvent::Type STOP = QEvent::Type(QEvent::User + 4);
 
+class RawTextureRecycler {
+public:
+    using TexturePtr = GLuint;
+    RawTextureRecycler(bool useMipmaps) : _useMipmaps(useMipmaps) {}
+    void setSize(const uvec2& size);
+    void clear();
+    TexturePtr getNextTexture();
+    void recycleTexture(GLuint texture);
+
+private:
+
+    struct TexInfo {
+        TexturePtr _tex { 0 };
+        uvec2 _size;
+        bool _active { false };
+
+        TexInfo() {}
+        TexInfo(TexturePtr tex, const uvec2& size) : _tex(tex), _size(size) {}
+    };
+
+    using Map = std::map<GLuint, TexInfo>;
+    using Queue = std::queue<TexturePtr>;
+
+    Map _allTextures;
+    Queue _readyTextures;
+    uvec2 _size { 1920, 1080 };
+    bool _useMipmaps;
+};
+
+
+void RawTextureRecycler::setSize(const uvec2& size) {
+    if (size == _size) {
+        return;
+    }
+    _size = size;
+    while (!_readyTextures.empty()) {
+        _readyTextures.pop();
+    }
+    std::set<Map::key_type> toDelete;
+    std::for_each(_allTextures.begin(), _allTextures.end(), [&](Map::const_reference item) {
+        if (!item.second._active && item.second._size != _size) {
+            toDelete.insert(item.first);
+        }
+    });
+    std::for_each(toDelete.begin(), toDelete.end(), [&](Map::key_type key) {
+        _allTextures.erase(key);
+    });
+}
+
+void RawTextureRecycler::clear() {
+    while (!_readyTextures.empty()) {
+        _readyTextures.pop();
+    }
+    _allTextures.clear();
+}
+
+RawTextureRecycler::TexturePtr RawTextureRecycler::getNextTexture() {
+    if (_readyTextures.empty()) {
+        TexturePtr newTexture;
+        glGenTextures(1, &newTexture);
+
+        glBindTexture(GL_TEXTURE_2D, newTexture);
+        if (_useMipmaps) {
+            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+        } else {
+            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+        }
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, 8.0f);
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_LOD_BIAS, -0.2f);
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, 8.0f); 
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, _size.x, _size.y, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
+        _allTextures[newTexture] = TexInfo { newTexture, _size };
+        _readyTextures.push(newTexture);
+    }
+
+    TexturePtr result = _readyTextures.front();
+    _readyTextures.pop();
+    auto& item = _allTextures[result];
+    item._active = true;
+    return result;
+}
+
+void RawTextureRecycler::recycleTexture(GLuint texture) {
+    Q_ASSERT(_allTextures.count(texture));
+    auto& item = _allTextures[texture];
+    Q_ASSERT(item._active);
+    item._active = false;
+    if (item._size != _size) {
+        // Buh-bye
+        _allTextures.erase(texture);
+        return;
+    }
+
+    _readyTextures.push(item._tex);
+}
+
+
 class OffscreenQmlRenderThread : public QThread {
 public:
     OffscreenQmlRenderThread(OffscreenQmlSurface* surface, QOpenGLContext* shareContext);
@@ -165,9 +271,9 @@ private:
     OffscreenQmlSurface* _surface{ nullptr };
     QQuickWindow* _quickWindow{ nullptr };
     QMyQuickRenderControl* _renderControl{ nullptr };
-    FramebufferPtr _fbo;
-    RenderbufferPtr _depthStencil;
-    TextureRecycler _textures { true };
+    GLuint _fbo { 0 };
+    GLuint _depthStencil { 0 };
+    RawTextureRecycler _textures { true };
     GLTextureEscrow _escrow;
 
     uint64_t _lastRenderTime{ 0 };
@@ -253,24 +359,23 @@ bool OffscreenQmlRenderThread::event(QEvent *e) {
 }
 
 void OffscreenQmlRenderThread::setupFbo() {
-    using namespace oglplus;
     _textures.setSize(_size);
-
-    try {
-        _depthStencil.reset(new Renderbuffer());
-        Context::Bound(Renderbuffer::Target::Renderbuffer, *_depthStencil)
-            .Storage(
-            PixelDataInternalFormat::DepthComponent,
-            _size.x, _size.y);
-
-        _fbo.reset(new Framebuffer());
-        _fbo->Bind(Framebuffer::Target::Draw);
-        _fbo->AttachRenderbuffer(Framebuffer::Target::Draw,
-            FramebufferAttachment::Depth, *_depthStencil);
-        DefaultFramebuffer().Bind(Framebuffer::Target::Draw);
-    } catch (oglplus::Error& error) {
-        qWarning() << "OpenGL error in QML render setup: " << error.what();
+    if (_depthStencil) {
+        glDeleteRenderbuffers(1, &_depthStencil);
+        _depthStencil = 0;
     }
+    glGenRenderbuffers(1, &_depthStencil);
+    glBindRenderbuffer(GL_RENDERBUFFER, _depthStencil);
+    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, _size.x, _size.y);
+
+    if (_fbo) {
+        glDeleteFramebuffers(1, &_fbo);
+        _fbo = 0;
+    }
+    glGenFramebuffers(1, &_fbo);
+    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, _fbo);
+    glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, _depthStencil);
+    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
 }
 
 QJsonObject OffscreenQmlRenderThread::getGLContextData() {
@@ -309,8 +414,15 @@ void OffscreenQmlRenderThread::init() {
 void OffscreenQmlRenderThread::cleanup() {
     _renderControl->invalidate();
 
-    _fbo.reset();
-    _depthStencil.reset();
+    if (_depthStencil) {
+        glDeleteRenderbuffers(1, &_depthStencil);
+        _depthStencil = 0;
+    }
+    if (_fbo) {
+        glDeleteFramebuffers(1, &_fbo);
+        _fbo = 0;
+    }
+
     _textures.clear();
 
     _canvas.doneCurrent();
@@ -371,42 +483,22 @@ void OffscreenQmlRenderThread::render() {
         releaseMainThread.trigger();
     }
 
-    using namespace oglplus;
-
-    _quickWindow->setRenderTarget(GetName(*_fbo), QSize(_size.x, _size.y));
+    _quickWindow->setRenderTarget(_fbo, QSize(_size.x, _size.y));
 
     try {
-        PROFILE_RANGE("qml_render")
-
-        TexturePtr texture = _textures.getNextTexture();
-
-        try {
-            _fbo->Bind(Framebuffer::Target::Draw);
-            _fbo->AttachTexture(Framebuffer::Target::Draw, FramebufferAttachment::Color, *texture, 0);
-            _fbo->Complete(Framebuffer::Target::Draw);
-        } catch (oglplus::Error& error) {
-            qWarning() << "OpenGL error in QML render: " << error.what();
-
-            // In case we are failing from a failed setupFbo, reset fbo before next render
-            setupFbo();
-            throw;
-        }
-
-        {
+        GLuint texture = _textures.getNextTexture();
+        glBindFramebuffer(GL_DRAW_FRAMEBUFFER, _fbo);
+        glFramebufferTexture(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, texture, 0);
             PROFILE_RANGE("qml_render->rendercontrol")
             _renderControl->render();
-            // FIXME The web browsers seem to be leaving GL in an error state.
-            // Need a debug context with sync logging to figure out why.
-            // for now just clear the errors
-            glGetError();
-        }
 
-        Context::Bound(oglplus::Texture::Target::_2D, *texture).GenerateMipmap();
+        glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
+        glBindTexture(GL_TEXTURE_2D, texture);
+        glGenerateMipmap(GL_TEXTURE_2D);
+        glBindTexture(GL_TEXTURE_2D, 0);
 
-        // FIXME probably unecessary
-        DefaultFramebuffer().Bind(Framebuffer::Target::Draw);
         _quickWindow->resetOpenGLState();
-        _escrow.submit(GetName(*texture));
+        _escrow.submit(texture);
         _lastRenderTime = usecTimestampNow();
     } catch (std::runtime_error& error) {
         qWarning() << "Failed to render QML: " << error.what();
diff --git a/libraries/gpu-gl/src/gpu/gl/GLTextureTransfer.cpp b/libraries/gpu-gl/src/gpu/gl/GLTextureTransfer.cpp
index 75af08d9a3..45403f4d4d 100644
--- a/libraries/gpu-gl/src/gpu/gl/GLTextureTransfer.cpp
+++ b/libraries/gpu-gl/src/gpu/gl/GLTextureTransfer.cpp
@@ -18,7 +18,6 @@
 std::unordered_map<TexturePointer, nvtxRangeId_t> _map;
 #endif
 
-//#define TEXTURE_TRANSFER_PBOS
 
 #ifdef TEXTURE_TRANSFER_PBOS
 #define TEXTURE_TRANSFER_BLOCK_SIZE (64 * 1024)
@@ -62,11 +61,16 @@ void GLTextureTransferHelper::transferTexture(const gpu::TexturePointer& texture
 void GLTextureTransferHelper::setup() {
 #ifdef THREADED_TEXTURE_TRANSFER
     _context.makeCurrent();
+
+#ifdef TEXTURE_TRANSFER_FORCE_DRAW
+    // FIXME don't use opengl 4.5 DSA functionality without verifying it's present
     glCreateRenderbuffers(1, &_drawRenderbuffer);
     glNamedRenderbufferStorage(_drawRenderbuffer, GL_RGBA8, 128, 128);
     glCreateFramebuffers(1, &_drawFramebuffer);
     glNamedFramebufferRenderbuffer(_drawFramebuffer, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, _drawRenderbuffer);
     glCreateFramebuffers(1, &_readFramebuffer);
+#endif
+
 #ifdef TEXTURE_TRANSFER_PBOS
     std::array<GLuint, TEXTURE_TRANSFER_PBO_COUNT> pbos;
     glCreateBuffers(TEXTURE_TRANSFER_PBO_COUNT, &pbos[0]);
@@ -84,7 +88,9 @@ void GLTextureTransferHelper::setup() {
 void GLTextureTransferHelper::shutdown() {
 #ifdef THREADED_TEXTURE_TRANSFER
     _context.makeCurrent();
+#endif
 
+#ifdef TEXTURE_TRANSFER_FORCE_DRAW
     glNamedFramebufferRenderbuffer(_drawFramebuffer, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, 0);
     glDeleteFramebuffers(1, &_drawFramebuffer);
     _drawFramebuffer = 0;
@@ -165,6 +171,11 @@ bool GLTextureTransferHelper::process() {
         }
 
         gltexture->finishTransfer();
+
+#ifdef TEXTURE_TRANSFER_FORCE_DRAW
+        // FIXME force a draw on the texture transfer thread before passing the texture to the main thread for use
+#endif
+
 #ifdef THREADED_TEXTURE_TRANSFER
         clientWait();
 #endif
diff --git a/libraries/gpu-gl/src/gpu/gl/GLTextureTransfer.h b/libraries/gpu-gl/src/gpu/gl/GLTextureTransfer.h
index 289aec40bb..a23c282fd4 100644
--- a/libraries/gpu-gl/src/gpu/gl/GLTextureTransfer.h
+++ b/libraries/gpu-gl/src/gpu/gl/GLTextureTransfer.h
@@ -21,6 +21,14 @@
 #define THREADED_TEXTURE_TRANSFER
 #endif
 
+#ifdef THREADED_TEXTURE_TRANSFER
+// FIXME when sparse textures are enabled, it's harder to force a draw on the transfer thread
+// also, the current draw code is implicitly using OpenGL 4.5 functionality
+//#define TEXTURE_TRANSFER_FORCE_DRAW
+// FIXME PBO's increase the complexity and don't seem to work reliably
+//#define TEXTURE_TRANSFER_PBOS
+#endif
+
 namespace gpu { namespace gl {
 
 using TextureList = std::list<TexturePointer>;
@@ -43,11 +51,15 @@ public:
 private:
 #ifdef THREADED_TEXTURE_TRANSFER
     ::gl::OffscreenContext _context;
+#endif
+
+#ifdef TEXTURE_TRANSFER_FORCE_DRAW
     // Framebuffers / renderbuffers for forcing access to the texture on the transfer thread
     GLuint _drawRenderbuffer { 0 };
     GLuint _drawFramebuffer { 0 };
     GLuint _readFramebuffer { 0 };
 #endif
+
     // A mutex for protecting items access on the render and transfer threads
     Mutex _mutex;
     // Commands that have been submitted for execution on the texture transfer thread
diff --git a/libraries/gpu-gl/src/gpu/gl45/GL45BackendTexture.cpp b/libraries/gpu-gl/src/gpu/gl45/GL45BackendTexture.cpp
index 6733475c01..3e6e53ffc3 100644
--- a/libraries/gpu-gl/src/gpu/gl45/GL45BackendTexture.cpp
+++ b/libraries/gpu-gl/src/gpu/gl45/GL45BackendTexture.cpp
@@ -16,8 +16,8 @@
 #include <unordered_map>
 #include <glm/gtx/component_wise.hpp>
 
+#include <QtCore/QDebug>
 #include <QtCore/QThread>
-#include <QtCore/QProcessEnvironment>
 
 #include "../gl/GLTexelFormat.h"
 
@@ -25,13 +25,6 @@ using namespace gpu;
 using namespace gpu::gl;
 using namespace gpu::gl45;
 
-#ifdef Q_OS_WIN
-static const QString DEBUG_FLAG("HIFI_DISABLE_SPARSE_TEXTURES");
-static bool enableSparseTextures = !QProcessEnvironment::systemEnvironment().contains(DEBUG_FLAG);
-#else
-static bool enableSparseTextures = false;
-#endif
-
 // Allocate 1 MB of buffer space for paged transfers
 #define DEFAULT_PAGE_BUFFER_SIZE (1024*1024)
 #define DEFAULT_GL_PIXEL_ALIGNMENT 4
@@ -253,7 +246,7 @@ GLuint GL45Backend::getTextureID(const TexturePointer& texture, bool transfer) {
 GL45Texture::GL45Texture(const std::weak_ptr<GLBackend>& backend, const Texture& texture, bool transferrable)
     : GLTexture(backend, texture, allocate(texture), transferrable), _sparseInfo(*this), _transferState(*this) {
 
-    if (enableSparseTextures && _transferrable) {
+    if (_transferrable && Texture::getEnableSparseTextures()) {
         _sparseInfo.maybeMakeSparse();
     }
 }
@@ -352,6 +345,31 @@ void GL45Texture::startTransfer() {
 }
 
 bool GL45Texture::continueTransfer() {
+    if (!Texture::getEnableIncrementalTextureTransfers()) {
+        size_t maxFace = GL_TEXTURE_CUBE_MAP == _target ? CUBE_NUM_FACES : 1;
+        for (uint8_t face = 0; face < maxFace; ++face) {
+            for (uint16_t mipLevel = _minMip; mipLevel <= _maxMip; ++mipLevel) {
+                if (_gpuObject.isStoredMipFaceAvailable(mipLevel, face)) {
+                    auto mip = _gpuObject.accessStoredMipFace(mipLevel, face);
+                    GLTexelFormat texelFormat = GLTexelFormat::evalGLTexelFormat(_gpuObject.getTexelFormat(), mip->getFormat());
+                    auto size = _gpuObject.evalMipDimensions(mipLevel);
+                    if (GL_TEXTURE_2D == _target) {
+                        glTextureSubImage2D(_id, mipLevel, 0, 0, size.x, size.y, texelFormat.format, texelFormat.type, mip->readData());
+                    } else if (GL_TEXTURE_CUBE_MAP == _target) {
+                        // DSA ARB does not work on AMD, so use EXT
+                        // glTextureSubImage3D(_id, mipLevel, 0, 0, face, size.x, size.y, 1, texelFormat.format, texelFormat.type, mip->readData());
+                        auto target = CUBE_FACE_LAYOUT[face];
+                        glTextureSubImage2DEXT(_id, target, mipLevel, 0, 0, size.x, size.y, texelFormat.format, texelFormat.type, mip->readData());
+                    } else {
+                        Q_ASSERT(false);
+                    }
+                    (void)CHECK_GL_ERROR();
+                }
+            }
+        }
+        return false;
+    }
+
     static std::vector<uint8_t> buffer;
     if (buffer.empty()) {
         buffer.resize(DEFAULT_PAGE_BUFFER_SIZE);
diff --git a/libraries/gpu/src/gpu/Texture.cpp b/libraries/gpu/src/gpu/Texture.cpp
index b573c8e899..44804abebe 100755
--- a/libraries/gpu/src/gpu/Texture.cpp
+++ b/libraries/gpu/src/gpu/Texture.cpp
@@ -9,6 +9,9 @@
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
 
+
+#include <QtCore/QDebug>
+
 #include "Texture.h"
 
 #include <glm/gtc/constants.hpp>
@@ -28,6 +31,34 @@ std::atomic<uint32_t> Texture::_textureCPUCount{ 0 };
 std::atomic<Texture::Size> Texture::_textureCPUMemoryUsage{ 0 };
 std::atomic<Texture::Size> Texture::_allowedCPUMemoryUsage { 0 };
 
+std::atomic<bool> Texture::_enableSparseTextures { false };
+std::atomic<bool> Texture::_enableIncrementalTextureTransfers { false };
+
+void Texture::setEnableSparseTextures(bool enabled) {
+#ifdef Q_OS_WIN
+    qDebug() << "[TEXTURE TRANSFER SUPPORT] SETTING - Enable Sparse Textures and Dynamic Texture Management:" << enabled;
+    _enableSparseTextures = enabled;
+    if (!_enableIncrementalTextureTransfers && _enableSparseTextures) {
+        qDebug() << "[TEXTURE TRANSFER SUPPORT] WARNING - Sparse texture management requires incremental texture transfer enabled.";
+    }
+#else
+    qDebug() << "[TEXTURE TRANSFER SUPPORT] Sparse Textures and Dynamic Texture Management not supported on this platform.";
+#endif
+}
+
+void Texture::setEnableIncrementalTextureTransfers(bool enabled) {
+#ifdef Q_OS_WIN
+    qDebug() << "[TEXTURE TRANSFER SUPPORT] SETTING - Enable Incremental Texture Transfer:" << enabled;
+    _enableIncrementalTextureTransfers = enabled;
+    if (!_enableIncrementalTextureTransfers && _enableSparseTextures) {
+        qDebug() << "[TEXTURE TRANSFER SUPPORT] WARNING - Sparse texture management requires incremental texture transfer enabled.";
+    }
+#else
+    qDebug() << "[TEXTURE TRANSFER SUPPORT] Incremental Texture Transfer not supported on this platform.";
+#endif
+}
+
+
 void Texture::updateTextureCPUMemoryUsage(Size prevObjectSize, Size newObjectSize) {
     if (prevObjectSize == newObjectSize) {
         return;
diff --git a/libraries/gpu/src/gpu/Texture.h b/libraries/gpu/src/gpu/Texture.h
index ae1afcafcb..61d03c070c 100755
--- a/libraries/gpu/src/gpu/Texture.h
+++ b/libraries/gpu/src/gpu/Texture.h
@@ -144,6 +144,9 @@ class Texture : public Resource {
     static std::atomic<Size> _textureCPUMemoryUsage;
     static std::atomic<Size> _allowedCPUMemoryUsage;
     static void updateTextureCPUMemoryUsage(Size prevObjectSize, Size newObjectSize);
+
+    static std::atomic<bool> _enableSparseTextures;
+    static std::atomic<bool> _enableIncrementalTextureTransfers;
 public:
     static uint32_t getTextureCPUCount();
     static Size getTextureCPUMemoryUsage();
@@ -154,6 +157,12 @@ public:
     static Size getAllowedGPUMemoryUsage();
     static void setAllowedGPUMemoryUsage(Size size);
 
+    static bool getEnableSparseTextures() { return _enableSparseTextures.load(); }
+    static bool getEnableIncrementalTextureTransfers() { return _enableIncrementalTextureTransfers.load(); }
+
+    static void setEnableSparseTextures(bool enabled);
+    static void setEnableIncrementalTextureTransfers(bool enabled);
+
     class Usage {
     public:
         enum FlagBit {
diff --git a/libraries/model-networking/src/model-networking/ModelCache.cpp b/libraries/model-networking/src/model-networking/ModelCache.cpp
index 306a19c308..6eacbab46a 100644
--- a/libraries/model-networking/src/model-networking/ModelCache.cpp
+++ b/libraries/model-networking/src/model-networking/ModelCache.cpp
@@ -377,8 +377,10 @@ void GeometryResource::deleter() {
 }
 
 void GeometryResource::setTextures() {
-    for (const FBXMaterial& material : _fbxGeometry->materials) {
-        _materials.push_back(std::make_shared<NetworkMaterial>(material, _textureBaseUrl));
+    if (_fbxGeometry) {
+        for (const FBXMaterial& material : _fbxGeometry->materials) {
+            _materials.push_back(std::make_shared<NetworkMaterial>(material, _textureBaseUrl));
+        }
     }
 }
 
@@ -457,7 +459,9 @@ model::TextureMapPointer NetworkMaterial::fetchTextureMap(const QUrl& baseUrl, c
     _textures[channel] = Texture { fbxTexture.name, texture };
 
     auto map = std::make_shared<model::TextureMap>();
-    map->setTextureSource(texture->_textureSource);
+    if (texture) {
+        map->setTextureSource(texture->_textureSource);
+    }
     map->setTextureTransform(fbxTexture.transform);
 
     return map;
diff --git a/libraries/model/src/model/Material.cpp b/libraries/model/src/model/Material.cpp
index 6e7968a571..4e01c4b866 100755
--- a/libraries/model/src/model/Material.cpp
+++ b/libraries/model/src/model/Material.cpp
@@ -44,8 +44,11 @@ Material::Material(const Material& material) :
 }
 
 Material& Material::operator= (const Material& material) {
+    QMutexLocker locker(&_textureMapsMutex);
+
     _key = (material._key);
     _textureMaps = (material._textureMaps);
+    _hasCalculatedTextureInfo = false;
 
     // copied: create the Buffer to store the properties, avoid holding a ref to the old Buffer
     Schema schema;
@@ -112,6 +115,8 @@ void Material::setScattering(float scattering) {
 }
 
 void Material::setTextureMap(MapChannel channel, const TextureMapPointer& textureMap) {
+    QMutexLocker locker(&_textureMapsMutex);
+
     if (textureMap) {
         _key.setMapChannel(channel, (true));
         _textureMaps[channel] = textureMap;
@@ -119,6 +124,7 @@ void Material::setTextureMap(MapChannel channel, const TextureMapPointer& textur
         _key.setMapChannel(channel, (false));
         _textureMaps.erase(channel);
     }
+    _hasCalculatedTextureInfo = false;
 
     _schemaBuffer.edit<Schema>()._key = (uint32)_key._flags.to_ulong();
 
@@ -173,6 +179,8 @@ void Material::resetOpacityMap() const {
 
 
 const TextureMapPointer Material::getTextureMap(MapChannel channel) const {
+    QMutexLocker locker(&_textureMapsMutex);
+
     auto result = _textureMaps.find(channel);
     if (result != _textureMaps.end()) {
         return (result->second);
@@ -180,3 +188,37 @@ const TextureMapPointer Material::getTextureMap(MapChannel channel) const {
         return TextureMapPointer();
     }
 }
+
+
+bool Material::calculateMaterialInfo() const {
+    if (!_hasCalculatedTextureInfo) {
+        QMutexLocker locker(&_textureMapsMutex);
+
+        bool allTextures = true; // assume we got this...
+        _textureSize = 0;
+        _textureCount = 0;
+
+        for (auto const &textureMapItem : _textureMaps) {
+            auto textureMap = textureMapItem.second;
+            if (textureMap) {
+                auto textureSoure = textureMap->getTextureSource();
+                if (textureSoure) {
+                    auto texture = textureSoure->getGPUTexture();
+                    if (texture) {
+                        auto size = texture->getSize();
+                        _textureSize += size;
+                        _textureCount++;
+                    } else {
+                        allTextures = false;
+                    }
+                } else {
+                    allTextures = false;
+                }
+            } else {
+                allTextures = false;
+            }
+        }
+        _hasCalculatedTextureInfo = allTextures;
+    }
+    return _hasCalculatedTextureInfo;
+}
diff --git a/libraries/model/src/model/Material.h b/libraries/model/src/model/Material.h
index 304ef2e93b..8851ef4ce9 100755
--- a/libraries/model/src/model/Material.h
+++ b/libraries/model/src/model/Material.h
@@ -11,6 +11,8 @@
 #ifndef hifi_model_Material_h
 #define hifi_model_Material_h
 
+#include <QMutex>
+
 #include <bitset>
 #include <map>
 
@@ -324,7 +326,7 @@ public:
 
     // The texture map to channel association
     void setTextureMap(MapChannel channel, const TextureMapPointer& textureMap);
-    const TextureMaps& getTextureMaps() const { return _textureMaps; }
+    const TextureMaps& getTextureMaps() const { return _textureMaps; } // FIXME - not thread safe... 
     const TextureMapPointer getTextureMap(MapChannel channel) const;
 
     // Albedo maps cannot have opacity detected until they are loaded
@@ -344,12 +346,25 @@ public:
     };
 
     const UniformBufferView& getTexMapArrayBuffer() const { return _texMapArrayBuffer; }
+
+    int getTextureCount() const { calculateMaterialInfo(); return _textureCount; }
+    size_t getTextureSize()  const { calculateMaterialInfo(); return _textureSize; }
+    bool hasTextureInfo() const { return _hasCalculatedTextureInfo; }
+
 private:
     mutable MaterialKey _key;
     mutable UniformBufferView _schemaBuffer;
     mutable UniformBufferView _texMapArrayBuffer;
 
     TextureMaps _textureMaps;
+
+    mutable QMutex _textureMapsMutex { QMutex::Recursive };
+    mutable size_t _textureSize { 0 };
+    mutable int _textureCount { 0 };
+    mutable bool _hasCalculatedTextureInfo { false };
+    bool calculateMaterialInfo() const;
+
+
 };
 typedef std::shared_ptr< Material > MaterialPointer;
 
diff --git a/libraries/networking/src/NodeList.cpp b/libraries/networking/src/NodeList.cpp
index 593a79b311..617ba85bad 100644
--- a/libraries/networking/src/NodeList.cpp
+++ b/libraries/networking/src/NodeList.cpp
@@ -536,15 +536,7 @@ void NodeList::processDomainServerList(QSharedPointer<ReceivedMessage> message)
     QUuid domainUUID;
     packetStream >> domainUUID;
 
-    // if this was the first domain-server list from this domain, we've now connected
-    if (!_domainHandler.isConnected()) {
-        _domainHandler.setUUID(domainUUID);
-        _domainHandler.setIsConnected(true);
-
-        // in case we didn't use a place name to get to this domain,
-        // give the address manager a chance to lookup a default one now
-        DependencyManager::get<AddressManager>()->lookupShareableNameForDomainID(domainUUID);
-    } else if (_domainHandler.getUUID() != domainUUID) {
+    if (_domainHandler.isConnected() && _domainHandler.getUUID() != domainUUID) {
         // Recieved packet from different domain.
         qWarning() << "IGNORING DomainList packet from" << domainUUID << "while connected to" << _domainHandler.getUUID();
         return;
@@ -555,6 +547,16 @@ void NodeList::processDomainServerList(QSharedPointer<ReceivedMessage> message)
     packetStream >> newUUID;
     setSessionUUID(newUUID);
 
+    // if this was the first domain-server list from this domain, we've now connected
+    if (!_domainHandler.isConnected()) {
+        _domainHandler.setUUID(domainUUID);
+        _domainHandler.setIsConnected(true);
+
+        // in case we didn't use a place name to get to this domain,
+        // give the address manager a chance to lookup a default one now
+        DependencyManager::get<AddressManager>()->lookupShareableNameForDomainID(domainUUID);
+    }
+
     // pull the permissions/right/privileges for this node out of the stream
     NodePermissions newPermissions;
     packetStream >> newPermissions;
diff --git a/libraries/render-utils/src/MeshPartPayload.cpp b/libraries/render-utils/src/MeshPartPayload.cpp
index 50c0c869ff..c791c1f98e 100644
--- a/libraries/render-utils/src/MeshPartPayload.cpp
+++ b/libraries/render-utils/src/MeshPartPayload.cpp
@@ -71,39 +71,8 @@ void MeshPartPayload::updateTransform(const Transform& transform, const Transfor
 
 void MeshPartPayload::updateMaterial(model::MaterialPointer drawMaterial) {
     _drawMaterial = drawMaterial;
-    calculateMaterialSize();
 }
 
-bool MeshPartPayload::calculateMaterialSize() {
-    bool allTextures = true; // assume we got this...
-    _materialTextureSize = 0;
-    _materialTextureCount = 0;
-    auto textureMaps = _drawMaterial->getTextureMaps();
-    for (auto const &textureMapItem : textureMaps) {
-        auto textureMap = textureMapItem.second;
-        if (textureMap) {
-            auto textureSoure = textureMap->getTextureSource();
-            if (textureSoure) {
-                auto texture = textureSoure->getGPUTexture();
-                if (texture) {
-                    //auto storedSize = texture->getStoredSize();
-                    auto size = texture->getSize();
-                    _materialTextureSize += size;
-                    _materialTextureCount++;
-                } else {
-                    allTextures = false;
-                }
-            } else {
-                allTextures = false;
-            }
-        } else {
-            allTextures = false;
-        }
-    }
-    return allTextures;
-}
-
-
 ItemKey MeshPartPayload::getKey() const {
     ItemKey::Builder builder;
     builder.withTypeShape();
@@ -378,7 +347,6 @@ void ModelMeshPartPayload::initCache() {
     auto networkMaterial = _model->getGeometry()->getShapeMaterial(_shapeID);
     if (networkMaterial) {
         _drawMaterial = networkMaterial;
-        calculateMaterialSize();
     }
 }
 
@@ -429,7 +397,12 @@ ItemKey ModelMeshPartPayload::getKey() const {
 }
 
 ShapeKey ModelMeshPartPayload::getShapeKey() const {
-    assert(_model->isLoaded());
+
+    // guard against partially loaded meshes
+    if (!_model || !_model->isLoaded() || !_model->getGeometry()) {
+        return ShapeKey::Builder::invalid();
+    }
+
     const FBXGeometry& geometry = _model->getFBXGeometry();
     const auto& networkMeshes = _model->getGeometry()->getMeshes();
 
diff --git a/libraries/render-utils/src/MeshPartPayload.h b/libraries/render-utils/src/MeshPartPayload.h
index 3ecd8da03e..04b63874cd 100644
--- a/libraries/render-utils/src/MeshPartPayload.h
+++ b/libraries/render-utils/src/MeshPartPayload.h
@@ -66,13 +66,9 @@ public:
     bool _hasColorAttrib = false;
 
     size_t getVerticesCount() const { return _drawMesh ? _drawMesh->getNumVertices() : 0; }
-    size_t getMaterialTextureSize() { return _materialTextureSize; }
-    int getMaterialTextureCount() { return _materialTextureCount; }
-    bool calculateMaterialSize();
-
-protected:
-    size_t _materialTextureSize { 0 };
-    int _materialTextureCount { 0 };
+    size_t getMaterialTextureSize() { return _drawMaterial ? _drawMaterial->getTextureSize() : 0; }
+    int getMaterialTextureCount() { return _drawMaterial ? _drawMaterial->getTextureCount() : 0; }
+    bool hasTextureInfo() const { return _drawMaterial ? _drawMaterial->hasTextureInfo() : false; }
 };
 
 namespace render {
diff --git a/libraries/render-utils/src/Model.cpp b/libraries/render-utils/src/Model.cpp
index f6caa7c3d3..28a1c3d579 100644
--- a/libraries/render-utils/src/Model.cpp
+++ b/libraries/render-utils/src/Model.cpp
@@ -168,10 +168,9 @@ void Model::calculateTextureInfo() {
         bool allTexturesLoaded = true;
         foreach(auto renderItem, _modelMeshRenderItemsSet) {
             auto meshPart = renderItem.get();
-            bool allTexturesForThisMesh = meshPart->calculateMaterialSize();
-            allTexturesLoaded = allTexturesLoaded & allTexturesForThisMesh;
             textureSize += meshPart->getMaterialTextureSize();
             textureCount += meshPart->getMaterialTextureCount();
+            allTexturesLoaded = allTexturesLoaded & meshPart->hasTextureInfo();
         }
         _renderInfoTextureSize = textureSize;
         _renderInfoTextureCount = textureCount;
diff --git a/libraries/script-engine/src/ScriptEngine.cpp b/libraries/script-engine/src/ScriptEngine.cpp
index 0ac2883cb5..160ad77197 100644
--- a/libraries/script-engine/src/ScriptEngine.cpp
+++ b/libraries/script-engine/src/ScriptEngine.cpp
@@ -517,10 +517,6 @@ void ScriptEngine::init() {
     // constants
     globalObject().setProperty("TREE_SCALE", newVariant(QVariant(TREE_SCALE)));
 
-    auto scriptingInterface = DependencyManager::get<controller::ScriptingInterface>();
-    registerGlobalObject("Controller", scriptingInterface.data());
-    UserInputMapper::registerControllerTypes(this);
-
     auto recordingInterface = DependencyManager::get<RecordingScriptingInterface>();
     registerGlobalObject("Recording", recordingInterface.data());
 
@@ -1021,9 +1017,12 @@ void ScriptEngine::updateMemoryCost(const qint64& deltaSize) {
 }
 
 void ScriptEngine::timerFired() {
-    if (DependencyManager::get<ScriptEngines>()->isStopped()) {
-        qCDebug(scriptengine) << "Script.timerFired() while shutting down is ignored... parent script:" << getFilename();
-        return; // bail early
+    {
+        auto engine = DependencyManager::get<ScriptEngines>();
+        if (!engine || engine->isStopped()) {
+            qCDebug(scriptengine) << "Script.timerFired() while shutting down is ignored... parent script:" << getFilename();
+            return; // bail early
+        }
     }
 
     QTimer* callingTimer = reinterpret_cast<QTimer*>(sender());
diff --git a/libraries/script-engine/src/ScriptEngine.h b/libraries/script-engine/src/ScriptEngine.h
index dd93dc2e03..62db99a431 100644
--- a/libraries/script-engine/src/ScriptEngine.h
+++ b/libraries/script-engine/src/ScriptEngine.h
@@ -166,7 +166,7 @@ public:
     void setUserLoaded(bool isUserLoaded) { _isUserLoaded = isUserLoaded; }
     bool isUserLoaded() const { return _isUserLoaded; }
 
-    // NOTE - this is used by the TypedArray implemetation. we need to review this for thread safety
+    // NOTE - this is used by the TypedArray implementation. we need to review this for thread safety
     ArrayBufferClass* getArrayBufferClass() { return _arrayBufferClass; }
 
     void setEmitScriptUpdatesFunction(std::function<bool()> func) { _emitScriptUpdates = func; }
diff --git a/server-console/src/content-update.css b/server-console/src/content-update.css
new file mode 100644
index 0000000000..9303e450b5
--- /dev/null
+++ b/server-console/src/content-update.css
@@ -0,0 +1,172 @@
+@font-face {
+    font-family: 'Raleway';
+    src: url('vendor/Raleway/Raleway-Regular.ttf');
+    font-weight: normal;
+    font-style: normal;
+}
+@font-face {
+    font-family: 'Raleway';
+    src: url('vendor/Raleway/Raleway-ExtraLight.ttf');
+    font-weight: 200;
+    font-style: normal;
+}
+@font-face {
+    font-family: 'Raleway';
+    src: url('vendor/Raleway/Raleway-SemiBold.ttf');
+    font-weight: bold;
+    font-style: normal;
+}
+
+
+* {
+    font-family: "Raleway", "Open Sans", Arial, Helvetica, sans-serif;
+    line-height: 130%;
+}
+
+body {
+    margin: 0;
+    padding: 0;
+    color: #808785;
+    margin: 0 auto;
+    text-align: left;
+    font-size: 13.5pt;
+    -webkit-touch-callout: none;    -webkit-user-select: none;
+    cursor: default;
+    overflow: hidden;
+    font-variant-numeric: lining-nums;
+    -moz-font-feature-settings: "lnum";
+    -webkit-font-feature-settings: "lnum";
+    font-feature-settings: "lnum";
+}
+
+.selectable {
+    -webkit-touch-callout: text;
+    -webkit-user-select: text;
+    cursor: text;
+}
+
+a:link,
+a:visited,
+a:hover,
+a:active {
+    color: #B4B4B4;
+}
+
+a:hover {
+    color: #2D88A4;
+}
+
+.header {
+   width: 95%;
+   left: 2.5%
+}
+.colmask {
+   width: 95%;
+   left: 2.5%
+}
+.colmid { right: 25% }
+.colin { right: 25% }
+.colleft { right: 25% }
+.col1 {
+   width: 23%;
+   left: 101%
+}
+.col2 {
+   width: 23%;
+   left: 53%
+}
+.col3 {
+   width: 23%;
+   left: 80%
+}
+.col4 {
+   width: 23%;
+   left: 82%
+}
+.footer {
+   width: 95%;
+   left: 2.5%
+}
+.header {
+   clear: both;
+   float: left;
+   position: relative;
+   border-bottom: #000 1px solid;
+   background-color: #b4d2f7
+}
+.colmask {
+   clear: both;
+   float: left;
+   overflow: hidden;
+   position: relative;
+
+}
+.colmid {
+   float: left;
+   width: 100%;
+   position: relative;
+
+}
+.colin {
+   float: left;
+   width: 100%;
+   position: relative;
+
+}
+.colleft {
+   float: left;
+   width: 100%;
+   position: relative;
+
+}
+.col1 {
+   padding: 0px 0px 1em 0px;
+   overflow: hidden;
+   float: left;
+   position: relative;
+
+}
+.col2 {
+   padding: 0px 0px 1em 0px;
+   overflow: hidden;
+   float: left;
+   position: relative;
+
+}
+.col3 {
+   padding: 0px 0px 1em 0px;
+   overflow: hidden;
+   float: left;
+   position: relative;
+
+}
+.col4 {
+   padding: 0px 0px 1em 0px;
+   overflow: hidden;
+   float: left;
+   position: relative;
+
+}
+.footer {
+   clear: both;
+   float: left;
+   position: relative;
+   padding-top: 8px;
+   border-top: #000 1px solid;
+
+}
+.bottom {
+   clear: both;
+   width: 100%;
+   float: left;
+   position: relative;
+
+}
+body {
+   border-width: 0px;
+   padding: 0px;
+   margin: 0px;
+   font-size: 90%;
+   width: 100%;
+   min-width: 600px;
+}
diff --git a/server-console/src/content-update.html b/server-console/src/content-update.html
new file mode 100644
index 0000000000..c4ed14473a
--- /dev/null
+++ b/server-console/src/content-update.html
@@ -0,0 +1,53 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Server Backup</title>
+    <script src="content-update.js"></script>
+    <link rel="stylesheet" type="text/css" href="content-update.css"></link>
+</head>
+<body onload="ready()">
+    <div class="colmask">
+        <h3>We backed up your old Sandbox content, just in case.</h3>
+        <p><b>To restore it, follow these steps:</b>
+
+        <div class="colmid">
+            <div class="colin">
+
+                <div class="colleft">
+
+                    <!--  I know the content of the columns are swapped -->
+                    <!--  If you manage to fix the CSS, you get to swap it back! -->
+                    <div class="col1">
+                        <img src="images/step2.jpg" alt="Step 2">
+                        <p><b>2.</b> Go to your backup directory:
+                        <span id="directory"></span>
+                    </div>
+
+                    <div class="col2">
+                        <img src="images/step1.jpg" alt="Step 1">
+                        <p><b>1.</b> Stop your Sandbox server.
+                    </div>
+
+                    <div class="col3">
+                      <img src="images/step3.jpg" alt="Step 3">
+                      <p><b>3.</b> Copy the backed up content and paste it into the parent directory.
+                    </div>
+
+                    <div class="col4">
+                      <img src="images/step4.jpg" alt="Step 4">
+                      <p><b>4.</b> Restart your Sandbox server.
+                    </div>
+
+                </div>
+
+            </div>
+
+        </div>
+
+        <div class="footer">
+
+         <p>For more information about managing your high Fidelity Sandbox Server, check out our docs: <a href="https://wiki.highfidelity.com/wiki/Sandbox" target="_blank">wiki.highfidelity.com/wiki/Sandbox</a>
+    </div>
+</div>
+</body>
+</html>
diff --git a/server-console/src/content-update.js b/server-console/src/content-update.js
new file mode 100644
index 0000000000..c77cfc92c6
--- /dev/null
+++ b/server-console/src/content-update.js
@@ -0,0 +1,12 @@
+function ready() {
+    console.log("Ready");
+
+    const electron = require('electron');
+    window.$ = require('./vendor/jquery/jquery-2.1.4.min.js');
+
+    electron.ipcRenderer.on('update', function(event, message) {
+        $('#directory').html(message);
+    });
+
+    electron.ipcRenderer.send('ready');
+}
diff --git a/server-console/src/images/step1.jpg b/server-console/src/images/step1.jpg
new file mode 100644
index 0000000000..cd80ae5537
Binary files /dev/null and b/server-console/src/images/step1.jpg differ
diff --git a/server-console/src/images/step2.jpg b/server-console/src/images/step2.jpg
new file mode 100644
index 0000000000..6bc285ac47
Binary files /dev/null and b/server-console/src/images/step2.jpg differ
diff --git a/server-console/src/images/step3.jpg b/server-console/src/images/step3.jpg
new file mode 100644
index 0000000000..a819dd2cdb
Binary files /dev/null and b/server-console/src/images/step3.jpg differ
diff --git a/server-console/src/images/step4.jpg b/server-console/src/images/step4.jpg
new file mode 100644
index 0000000000..27694aee74
Binary files /dev/null and b/server-console/src/images/step4.jpg differ
diff --git a/server-console/src/main.js b/server-console/src/main.js
index 82fe6b6b4d..e297ca3276 100644
--- a/server-console/src/main.js
+++ b/server-console/src/main.js
@@ -408,6 +408,13 @@ var labels = {
             logWindow.open();
         }
     },
+    restoreBackup: {
+        label: 'Restore Backup Instructions',
+        click: function() {
+            var folder = getRootHifiDataDirectory() + "/Server Backup";
+            openBackupInstructions(folder);
+        }
+    },
     share: {
         label: 'Share',
         click: function() {
@@ -443,6 +450,7 @@ function buildMenuArray(serverState) {
         menuArray.push(labels.stopServer);
         menuArray.push(labels.settings);
         menuArray.push(labels.viewLogs);
+        menuArray.push(labels.restoreBackup);
         menuArray.push(separator);
         menuArray.push(labels.share);
         menuArray.push(separator);
@@ -488,27 +496,60 @@ function updateTrayMenu(serverState) {
 
 const httpStatusPort = 60332;
 
-function deleteResourceDirectories() {
-    const dsResourceDirectory = getDomainServerClientResourcesDirectory();
+function backupResourceDirectories(folder) {
     try {
-        fs.removeSync(dsResourceDirectory);
-        console.log("Deleted directory " + dsResourceDirectory);
-    } catch (e) {
-        console.log(e);
-    }
-    const acResourceDirectory = getAssignmentClientResourcesDirectory();
-    try {
-        fs.removeSync(acResourceDirectory);
-        console.log("Deleted directory " + acResourceDirectory);
+        fs.mkdirSync(folder);
+        console.log("Created directory " + folder);
+
+        var dsBackup = path.join(folder, '/domain-server');
+        var acBackup = path.join(folder, '/assignment-client');
+
+        fs.copySync(getDomainServerClientResourcesDirectory(), dsBackup);
+        fs.copySync(getAssignmentClientResourcesDirectory(), acBackup);
+
+        fs.removeSync(getDomainServerClientResourcesDirectory());
+        fs.removeSync(getAssignmentClientResourcesDirectory());
+
+        return true;
     } catch (e) {
         console.log(e);
+        return false;
     }
 }
 
-function deleteResourceDirectoriesAndRestart() {
+function openBackupInstructions(folder) {
+    // Explain user how to restore server
+    var window = new BrowserWindow({
+        icon: appIcon,
+        width: 800,
+        height: 520,
+    });
+    window.loadURL('file://' + __dirname + '/content-update.html');
+    if (!debug) {
+        window.setMenu(null);
+    }
+    window.show();
+
+    electron.ipcMain.on('ready', function() {
+        console.log("got ready");
+        window.webContents.send('update', folder);
+    });
+}
+function backupResourceDirectoriesAndRestart() {
     homeServer.stop();
-    deleteResourceDirectories();
-    maybeInstallDefaultContentSet(onContentLoaded);
+
+    var folder = getRootHifiDataDirectory() + "/Server Backup - " + Date.now();
+    if (backupResourceDirectories(folder)) {
+        maybeInstallDefaultContentSet(onContentLoaded);
+        openBackupInstructions(folder);
+    } else {
+        dialog.showMessageBox({
+            type: 'warning',
+            buttons: ['Ok'],
+            title: 'Update Error',
+            message: 'There was an error updating the content, aborting.'
+        }, function() {});
+    }
 }
 
 function checkNewContent() {
@@ -537,16 +578,7 @@ function checkNewContent() {
                   message: 'A newer version of the home content set is available.\nDo you wish to update?'
               }, function(idx) {
                 if (idx === 0) {
-                  dialog.showMessageBox({
-                      type: 'question',
-                      buttons: ['Yes', 'No'],
-                      title: 'Are you sure?',
-                      message: 'This action will delete your current sandbox content.\nDo you wish to continue?'
-                  }, function(idx) {
-                    if (idx === 0 && homeServer) {
-                        deleteResourceDirectoriesAndRestart();
-                    }
-                  });
+                  backupResourceDirectoriesAndRestart();
                 } else {
                   // They don't want to update, mark content set as current
                   userConfig.set('homeContentLastModified', new Date());