diff --git a/libraries/entities/src/EntityScriptingInterface.cpp b/libraries/entities/src/EntityScriptingInterface.cpp
index 01892b2783..605c0b8d86 100644
--- a/libraries/entities/src/EntityScriptingInterface.cpp
+++ b/libraries/entities/src/EntityScriptingInterface.cpp
@@ -132,7 +132,7 @@ void EntityScriptingInterface::releaseEntityPacketSenderMessages(bool wait) {
 void EntityScriptingInterface::attachDefaultEventHandlers(ScriptManager* manager) {
     // Connect up ALL the handlers to the global entities object's signals.
     // (We could go signal by signal, or even handler by handler, but I don't think the efficiency is worth the complexity.)
-    
+
     // Bug? These handlers are deleted when entityID is deleted, which is nice.
     // But if they are created by an entity script on a different entity, should they also be deleted when the entity script unloads?
     // E.g., suppose a bow has an entity script that causes arrows to be created with a potential lifetime greater than the bow,
@@ -194,7 +194,7 @@ void EntityScriptingInterface::attachDefaultEventHandlers(ScriptManager* manager
     };
 
     /*@jsdoc
-         * <p>The name of an entity event. When the entity event occurs, any function that has been registered for that event 
+         * <p>The name of an entity event. When the entity event occurs, any function that has been registered for that event
          * via {@link Script.addEventHandler} is called with parameters per the entity event.</p>
          * <table>
          *   <thead>
@@ -782,7 +782,7 @@ QUuid EntityScriptingInterface::cloneEntity(const QUuid& entityIDToClone) {
     } else if (cloneAvatarEntity) {
         return addEntityInternal(properties, entity::HostType::AVATAR);
     } else {
-        // setLastEdited timestamp to 0 to ensure this entity gets updated with the properties 
+        // setLastEdited timestamp to 0 to ensure this entity gets updated with the properties
         // from the server-created entity, don't change this unless you know what you are doing
         properties.setLastEdited(0);
         bool success = addLocalEntityCopy(properties, newEntityID, true);
@@ -1255,7 +1255,7 @@ void EntityScriptingInterface::setNonPersistentEntitiesScriptEngine(std::shared_
 
 void EntityScriptingInterface::callEntityMethod(const QUuid& id, const QString& method, const QStringList& params) {
     PROFILE_RANGE(script_entities, __FUNCTION__);
-    
+
     auto entity = getEntityTree()->findEntityByEntityItemID(id);
     if (entity) {
         std::lock_guard<std::recursive_mutex> lock(_entitiesScriptEngineLock);
@@ -1605,7 +1605,7 @@ bool EntityScriptingInterface::queryPropertyMetadata(const QUuid& entityID,
 #endif
     if (!handler.property("callback").isFunction()) {
         qDebug() << "!handler.callback.isFunction" << manager;
-        engine->raiseException(engine->makeError(engine->newValue("callback is not a function"), "TypeError"));
+        engine->raiseException("callback is not a function", "TypeError");
         return false;
     }
 
@@ -1628,8 +1628,7 @@ bool EntityScriptingInterface::queryPropertyMetadata(const QUuid& entityID,
     } else if (name == "serverScripts") {
         return request.serverScripts(entityID, handler);
     } else {
-        engine->raiseException(engine->makeError(engine->newValue("metadata for property " + name + " is not yet queryable")));
-        engine->maybeEmitUncaughtException(__FUNCTION__);
+        engine->raiseException("metadata for property " + name + " is not yet queryable");
         return false;
     }
 }
@@ -1644,8 +1643,7 @@ bool EntityScriptingInterface::getServerScriptStatus(const QUuid& entityID, Scri
     Q_ASSERT(QThread::currentThread() == engine->thread());
     Q_ASSERT(QThread::currentThread() == engine->manager()->thread());
     if (!manager) {
-        engine->raiseException(engine->makeError(engine->newValue("This script does not belong to a ScriptManager")));
-        engine->maybeEmitUncaughtException(__FUNCTION__);
+        engine->raiseException("This script does not belong to a ScriptManager");
         return false;
     }
 
@@ -2015,17 +2013,17 @@ EntityItemPointer EntityScriptingInterface::checkForTreeEntityAndTypeMatch(const
     if (!_entityTree) {
         return EntityItemPointer();
     }
-    
+
     EntityItemPointer entity = _entityTree->findEntityByEntityItemID(entityID);
     if (!entity) {
         qCDebug(entities) << "EntityScriptingInterface::checkForTreeEntityAndTypeMatch - no entity with ID" << entityID;
         return entity;
     }
-    
+
     if (entityType != EntityTypes::Unknown && entity->getType() != entityType) {
         return EntityItemPointer();
     }
-    
+
     return entity;
 }
 
diff --git a/libraries/script-engine/src/ScriptEngine.h b/libraries/script-engine/src/ScriptEngine.h
index 5e60c79238..bbefed3147 100644
--- a/libraries/script-engine/src/ScriptEngine.h
+++ b/libraries/script-engine/src/ScriptEngine.h
@@ -179,14 +179,6 @@ public:
      */
     virtual void clearExceptions() = 0;
 
-    /**
-     * @brief Creates a clone of the current exception
-     *
-     * @param detail Additional text to add to the report
-     * @return ScriptValue Result
-     */
-    virtual ScriptValue cloneUncaughtException(const QString& detail = QString()) = 0;
-
     /**
      * @brief Context of the currently running script
      *
@@ -274,15 +266,6 @@ public:
      */
     virtual ScriptValue checkScriptSyntax(ScriptProgramPointer program) = 0;
 
-    /**
-     * @brief Creates a ScriptValue that contains an error
-     *
-     * @param other
-     * @param type
-     * @return ScriptValue
-     */
-    virtual ScriptValue makeError(const ScriptValue& other = ScriptValue(), const QString& type = "Error") = 0;
-
     /**
      * @brief Pointer to the ScriptManager that controls this scripting engine
      *
@@ -290,19 +273,6 @@ public:
      */
     ScriptManager* manager() const { return _manager; }
 
-    /**
-     * @brief Emit the current uncaught exception if there is one
-     *
-     * If there's an uncaught exception, emit it, and clear the exception status.
-     *
-     * This fails if there's no uncaught exception, there's no ScriptManager,
-     * or the engine is evaluating.
-     *
-     * @param debugHint A debugging hint to be added to the error message
-     * @return true There was an uncaught exception, and it was emitted
-     * @return false There was no uncaught exception
-     */
-    virtual bool maybeEmitUncaughtException(const QString& debugHint = QString()) = 0;
     virtual ScriptValue newArray(uint length = 0) = 0;
     virtual ScriptValue newArrayBuffer(const QByteArray& message) = 0;
     virtual ScriptValue newFunction(FunctionSignature fun, int length = 0) {
@@ -323,14 +293,39 @@ public:
     virtual ScriptValue nullValue() = 0;
 
 
+    /**
+     * @brief Make a ScriptValue that contains an error
+     *
+     * This is used to throw an error inside the running script
+     *
+     * @param other
+     * @param type
+     * @return ScriptValue ScriptValue containing error
+     */
+    virtual ScriptValue makeError(const ScriptValue& other, const QString& type = "Error") = 0;
+
+
     /**
      * @brief Causes an exception to be raised in the currently executing script
      *
      * @param exception Exception to be thrown in the script
+     * @param reason Explanatory text about why the exception happened, for logging
      * @return true Exception was successfully thrown
      * @return false Exception couldn't be thrown because no script is running
      */
-    virtual bool raiseException(const ScriptValue& exception) = 0;
+    virtual bool raiseException(const ScriptValue& exception, const QString &reason = QString()) = 0;
+
+    /**
+     * @brief Causes an exception to be raised in the currently executing script
+     *
+     * @param error Exception to be thrown in the script
+     * @param reason Explanatory text about why the exception happened, for logging
+     * @return true Exception was successfully thrown
+     * @return false Exception couldn't be thrown because no script is running
+     */
+    virtual bool raiseException(const QString& error, const QString &reason = QString()) = 0;
+
+
     virtual void registerEnum(const QString& enumName, QMetaEnum newEnum) = 0;
     virtual void registerFunction(const QString& name, FunctionSignature fun, int numArguments = -1) = 0;
     virtual void registerFunction(const QString& parent, const QString& name, FunctionSignature fun, int numArguments = -1) = 0;
@@ -346,11 +341,14 @@ public:
     virtual ScriptValue undefinedValue() = 0;
 
     /**
-     * @brief Last uncaught exception, if any
+     * @brief Last uncaught exception, if any.
      *
-     * @return ScriptValue Uncaught exception from the script
+     * The returned shared pointer is newly allocated by the function,
+     * and modifying it has no effect on the internal state of the ScriptEngine.
+     *
+     * @return std::shared_ptr<ScriptValue> Uncaught exception from the script
      */
-    virtual ScriptException uncaughtException() const = 0;
+    virtual std::shared_ptr<ScriptException> uncaughtException() const = 0;
 
     virtual void updateMemoryCost(const qint64& deltaSize) = 0;
     virtual void requestCollectGarbage() = 0;
@@ -403,7 +401,7 @@ signals:
      *
      * @param exception Exception that was thrown
      */
-    void exception(const ScriptException &exception);
+    void exception(std::shared_ptr<ScriptException> exception);
 
 protected:
     ~ScriptEngine() {}  // prevent explicit deletion of base class
diff --git a/libraries/script-engine/src/ScriptException.h b/libraries/script-engine/src/ScriptException.h
index 174099bb4d..89a48fa4b2 100644
--- a/libraries/script-engine/src/ScriptException.h
+++ b/libraries/script-engine/src/ScriptException.h
@@ -12,12 +12,15 @@
 #include <QString>
 #include <QStringList>
 
+#include "ScriptValue.h"
+
 #pragma once
 
 /**
  * @brief Scripting exception
  *
  * Emitted from the scripting engine when an exception happens inside it.
+ * This is the base class.
  *
  */
 class ScriptException {
@@ -63,6 +66,89 @@ class ScriptException {
     QStringList backtrace;
 
     bool isEmpty() const { return errorMessage.isEmpty(); }
+
+    /**
+     * @brief Clones this object.
+     *
+     * This is used in the scripting engine to ensure that while it can return different
+     * exception objects depending on what happened, the returned object is a copy that
+     * doesn't allow the caller to accidentally break the ScriptEngine's internal state.
+     *
+     * @return std::shared_ptr<ScriptException>
+     */
+    virtual std::shared_ptr<ScriptException> clone() const {
+        return std::make_shared<ScriptException>(*this);
+    }
+};
+
+
+/**
+ * @brief Exception that ocurred inside the scripting engine on the c++ side
+ *
+ * This is something that went wrong inside the ScriptEngine or ScriptManager
+ * infrastructure.
+ *
+ */
+class ScriptEngineException : public ScriptException {
+    public:
+
+    ScriptEngineException(QString message = "", QString info = "", int line = 0, int column = 0, QStringList backtraceList = QStringList()) :
+        ScriptException(message, info, line, column, backtraceList) {
+
+    }
+
+
+    /**
+     * @brief Clones this object.
+     *
+     * This is used in the scripting engine to ensure that while it can return different
+     * exception objects depending on what happened, the returned object is a copy that
+     * doesn't allow the caller to accidentally break the ScriptEngine's internal state.
+     *
+     * @return std::shared_ptr<ScriptException>
+     */
+    virtual std::shared_ptr<ScriptException> clone() const override {
+        return std::make_shared<ScriptEngineException>(*this);
+    }
+};
+
+
+
+/**
+ * @brief Exception that ocurred inside the running script
+ *
+ * This is something that went wrong inside the running script.
+ *
+ */
+class ScriptRuntimeException : public ScriptException {
+    public:
+
+    ScriptRuntimeException(QString message = "", QString info = "", int line = 0, int column = 0, QStringList backtraceList = QStringList()) :
+        ScriptException(message, info, line, column, backtraceList) {
+
+    }
+
+
+    /**
+     * @brief The actual value that was thrown by the script.
+     *
+     * The content is completely arbitrary.
+     *
+     */
+    ScriptValue thrownValue;
+
+    /**
+     * @brief Clones this object.
+     *
+     * This is used in the scripting engine to ensure that while it can return different
+     * exception objects depending on what happened, the returned object is a copy that
+     * doesn't allow the caller to accidentally break the ScriptEngine's internal state.
+     *
+     * @return std::shared_ptr<ScriptException>
+     */
+    virtual std::shared_ptr<ScriptException> clone() const override {
+        return std::make_shared<ScriptRuntimeException>(*this);
+    }
 };
 
 inline QDebug operator<<(QDebug debug, const ScriptException& e) {
@@ -76,5 +162,20 @@ inline QDebug operator<<(QDebug debug, const ScriptException& e) {
         debug << e.backtrace;
     }
 
+    return debug;
+}
+
+// Is this a bad practice?
+inline QDebug operator<<(QDebug debug, std::shared_ptr<ScriptException> e) {
+    debug << "Exception:"
+        << e->errorMessage
+        << (e->additionalInfo.isEmpty() ? QString("") : "[" + e->additionalInfo + "]")
+        << " at line " << e->errorLine << ", column " << e->errorColumn;
+
+    if (e->backtrace.length()) {
+        debug << "Backtrace:";
+        debug << e->backtrace;
+    }
+
     return debug;
 }
\ No newline at end of file
diff --git a/libraries/script-engine/src/ScriptManager.cpp b/libraries/script-engine/src/ScriptManager.cpp
index 46c3cacdf2..81b0e455fb 100644
--- a/libraries/script-engine/src/ScriptManager.cpp
+++ b/libraries/script-engine/src/ScriptManager.cpp
@@ -282,6 +282,11 @@ ScriptManager::ScriptManager(Context context, const QString& scriptContents, con
         processLevelMaxRetries = 1;
     }
 
+
+#if 0
+    // V8TODO: Is this actually needed? Exceptions will already be logged on the
+    // script engine side.
+
     // this is where all unhandled exceptions end up getting logged
     connect(this, &ScriptManager::unhandledException, this, [this](const ScriptValue& err) {
         qCCritical(scriptengine) << "Caught exception";
@@ -296,6 +301,7 @@ ScriptManager::ScriptManager(Context context, const QString& scriptContents, con
 
         logException(output);
     });
+#endif
 
     if (_type == Type::ENTITY_CLIENT || _type == Type::ENTITY_SERVER) {
         QObject::connect(this, &ScriptManager::update, this, [this]() {
@@ -891,13 +897,11 @@ void ScriptManager::run() {
     {
         PROFILE_RANGE(script, _fileNameString);
         _returnValue = _engine->evaluate(_scriptContents, _fileNameString);
-        _engine->maybeEmitUncaughtException(__FUNCTION__);
 
         if (_engine->hasUncaughtException()) {
 
             qCWarning(scriptengine) << "Engine has uncaught exception, stopping";
             stop();
-            emit unhandledException(_engine->cloneUncaughtException(__FUNCTION__));
             _engine->clearExceptions();
         }
     }
@@ -1023,7 +1027,7 @@ void ScriptManager::run() {
         if (!_engine->isEvaluating() && _engine->hasUncaughtException()) {
             qCWarning(scriptengine) << __FUNCTION__ << "---------- UNCAUGHT EXCEPTION --------";
             qCWarning(scriptengine) << "runInThread" << _engine->uncaughtException();
-            emit unhandledException(_engine->cloneUncaughtException(__FUNCTION__));
+            emit unhandledException(_engine->uncaughtException());
             _engine->clearExceptions();
         }
     }
@@ -1258,9 +1262,8 @@ QString ScriptManager::_requireResolve(const QString& moduleId, const QString& r
     }
     auto message = QString("Cannot find module '%1' (%2)").arg(displayId);
 
-    auto throwResolveError = [&](const ScriptValue& error) -> QString {
-        _engine->raiseException(error);
-        _engine->maybeEmitUncaughtException("require.resolve");
+    auto throwResolveError = [&](const QString& error, const QString &details = QString()) -> QString {
+        _engine->raiseException(error, "require.resolve: " + details);
         return QString();
     };
 
@@ -1269,7 +1272,7 @@ QString ScriptManager::_requireResolve(const QString& moduleId, const QString& r
     if (idLength < 1 || idLength > MAX_MODULE_ID_LENGTH) {
         auto details = QString("rejecting invalid module id size (%1 chars [1,%2])")
             .arg(idLength).arg(MAX_MODULE_ID_LENGTH);
-        return throwResolveError(_engine->makeError(_engine->newValue(message.arg(details)), "RangeError"));
+        return throwResolveError(details, "RangeError");
     }
 
     // this regex matches: absolute, dotted or path-like URLs
@@ -1296,15 +1299,15 @@ QString ScriptManager::_requireResolve(const QString& moduleId, const QString& r
                 if (QFileInfo(unanchoredUrl.toLocalFile()).isFile()) {
                     auto msg = QString("relative module ids must be anchored; use './%1' instead")
                         .arg(moduleId);
-                    return throwResolveError(_engine->makeError(_engine->newValue(message.arg(msg))));
+                    return throwResolveError(message.arg(msg));
                 }
             }
-            return throwResolveError(_engine->makeError(_engine->newValue(message.arg("system module not found"))));
+            return throwResolveError(message.arg("system module not found"));
         }
     }
 
     if (url.isRelative()) {
-        return throwResolveError(_engine->makeError(_engine->newValue(message.arg("could not resolve module id"))));
+        return throwResolveError(message.arg("could not resolve module id"));
     }
 
     // if it looks like a local file, verify that it's an allowed path and really a file
@@ -1317,22 +1320,21 @@ QString ScriptManager::_requireResolve(const QString& moduleId, const QString& r
 
         bool disallowOutsideFiles = !PathUtils::defaultScriptsLocation().isParentOf(canonical) && !currentSandboxURL.isLocalFile();
         if (disallowOutsideFiles && !PathUtils::isDescendantOf(canonical, currentSandboxURL)) {
-            return throwResolveError(_engine->makeError(_engine->newValue(message.arg(
+            return throwResolveError(message.arg(
                 QString("path '%1' outside of origin script '%2' '%3'")
                     .arg(PathUtils::stripFilename(url))
                     .arg(PathUtils::stripFilename(currentSandboxURL))
                     .arg(canonical.toString())
-            ))));
+            ));
         }
         if (!file.exists()) {
-            return throwResolveError(_engine->makeError(_engine->newValue(message.arg("path does not exist: " + url.toLocalFile()))));
+            return throwResolveError(message.arg("path does not exist: " + url.toLocalFile()));
         }
         if (!file.isFile()) {
-            return throwResolveError(_engine->makeError(_engine->newValue(message.arg("path is not a file: " + url.toLocalFile()))));
+            return throwResolveError(message.arg("path is not a file: " + url.toLocalFile()));
         }
     }
 
-    _engine->maybeEmitUncaughtException(__FUNCTION__);
     return url.toString();
 }
 
@@ -1488,7 +1490,7 @@ ScriptValue ScriptManager::instantiateModule(const ScriptValue& module, const QS
         //_engine->scriptValueDebugDetails(module);
         result = _engine->evaluateInClosure(closure, _engine->newProgram( sourceCode, modulePath ));
     }
-    _engine->maybeEmitUncaughtException(__FUNCTION__);
+
     return result;
 }
 
@@ -1510,9 +1512,8 @@ ScriptValue ScriptManager::require(const QString& moduleId) {
 #ifdef DEBUG_JS_MODULES
             qCWarning(scriptengine_module) << "throwing module error:" << error.toString() << modulePath << error.property("stack").toString();
 #endif
-            _engine->raiseException(error);
+            _engine->raiseException(error, "module error");
         }
-        _engine->maybeEmitUncaughtException("module");
         return _engine->nullValue();
     };
 
@@ -1520,7 +1521,6 @@ ScriptValue ScriptManager::require(const QString& moduleId) {
     QString modulePath = _requireResolve(moduleId);
     if (modulePath.isNull() || _engine->hasUncaughtException()) {
         // the resolver already threw an exception -- bail early
-        _engine->maybeEmitUncaughtException(__FUNCTION__);
         return _engine->nullValue();
     }
 
@@ -1546,7 +1546,6 @@ ScriptValue ScriptManager::require(const QString& moduleId) {
         qCDebug(scriptengine_module) << QString("require - using cached module for '%1' (loaded: %2)")
             .arg(moduleId).arg(module.property("loaded").toString());
         registerModuleWithParent(module, parent);
-        _engine->maybeEmitUncaughtException("cached module");
         return exports;
     }
 
@@ -1594,7 +1593,6 @@ ScriptValue ScriptManager::require(const QString& moduleId) {
 
     //qCDebug(scriptengine_module) << "//ScriptManager::require(" << moduleId << ")";
 
-    _engine->maybeEmitUncaughtException(__FUNCTION__);
     //qCDebug(scriptengine_module) << "Exports: " << _engine->scriptValueDebugDetails(module.property("exports"));
     return module.property("exports");
 }
@@ -1670,7 +1668,9 @@ void ScriptManager::include(const QStringList& includeFiles, const ScriptValue&
 
                     doWithEnvironment(capturedEntityIdentifier, capturedSandboxURL, operation);
                     if(_engine->hasUncaughtException()) {
-                        emit unhandledException(_engine->cloneUncaughtException("evaluateInclude"));
+                        auto ex = _engine->uncaughtException();
+                        ex->additionalInfo += "; evaluateInClosure";
+                        emit unhandledException(ex);
                         _engine->clearExceptions();
                     }
                 } else {
@@ -1995,11 +1995,14 @@ void ScriptManager::entityScriptContentAvailable(const EntityItemID& entityID, c
         //syntaxError.setProperty("detail", entityID.toString());
         //V8TODO
         //emit unhandledException(syntaxError);
+
         return;
     }
     if (!program) {
         setError("Bad program (isNull)", EntityScriptStatus::ERROR_RUNNING_SCRIPT);
-        emit unhandledException(_engine->makeError(_engine->newValue("program.isNull")));
+        std::shared_ptr<ScriptException> ex = std::make_shared<ScriptEngineException>("Program is Null", "Bad program in entityScriptContentAvailable");
+        emit unhandledException(ex);
+
         return; // done processing script
     }
 
@@ -2163,7 +2166,10 @@ void ScriptManager::entityScriptContentAvailable(const EntityItemID& entityID, c
         entityScriptObject = entityScriptConstructor.construct();
 
         if (_engine->hasUncaughtException()) {
-            entityScriptObject = _engine->cloneUncaughtException("(construct " + entityID.toString() + ")");
+            // V8TODO: Why were we copying the uncaught exception here? Does anything
+            // actually make use of that?
+            //  entityScriptObject = _engine->cloneUncaughtException("(construct " + entityID.toString() + ")");
+            entityScriptObject = _engine->nullValue();
             _engine->clearExceptions();
         }
     };
@@ -2171,9 +2177,10 @@ void ScriptManager::entityScriptContentAvailable(const EntityItemID& entityID, c
     doWithEnvironment(entityID, sandboxURL, initialization);
 
     if (entityScriptObject.isError()) {
-        auto exception = entityScriptObject;
-        setError(formatException(exception, _enableExtendedJSExceptions.get()), EntityScriptStatus::ERROR_RUNNING_SCRIPT);
-        emit unhandledException(exception);
+       // auto exception = entityScriptObject;
+       // setError(formatException(exception, _enableExtendedJSExceptions.get()), EntityScriptStatus::ERROR_RUNNING_SCRIPT);
+       // emit unhandledException(exception);
+       // V8TODO: Is this needed? Wouldn't the ScriptManager have already emitted the exception?
         return;
     }
 
@@ -2340,7 +2347,6 @@ void ScriptManager::doWithEnvironment(const EntityItemID& entityID, const QUrl&
 #else
     operation();
 #endif
-    _engine->maybeEmitUncaughtException(!entityID.isNull() ? entityID.toString() : __FUNCTION__);
     currentEntityIdentifier = oldIdentifier;
     currentSandboxURL = oldSandboxURL;
 }
diff --git a/libraries/script-engine/src/ScriptManager.h b/libraries/script-engine/src/ScriptManager.h
index 60cdc0a670..514a182d20 100644
--- a/libraries/script-engine/src/ScriptManager.h
+++ b/libraries/script-engine/src/ScriptManager.h
@@ -46,6 +46,7 @@
 #include "Quat.h"
 #include "ScriptUUID.h"
 #include "ScriptValue.h"
+#include "ScriptException.h"
 #include "Vec3.h"
 
 static const QString NO_SCRIPT("");
@@ -1326,7 +1327,7 @@ signals:
      *
      * @param exception
      */
-    void unhandledException(const ScriptValue& exception);
+    void unhandledException(std::shared_ptr<ScriptException> exception);
 
     ///@}
 
diff --git a/libraries/script-engine/src/ScriptManagerScriptingInterface.cpp b/libraries/script-engine/src/ScriptManagerScriptingInterface.cpp
index f8a475e201..31b536b197 100644
--- a/libraries/script-engine/src/ScriptManagerScriptingInterface.cpp
+++ b/libraries/script-engine/src/ScriptManagerScriptingInterface.cpp
@@ -30,5 +30,12 @@
         connect(_manager, &ScriptManager::doneRunning, this, &ScriptManagerScriptingInterface::doneRunning);
         connect(_manager, &ScriptManager::entityScriptDetailsUpdated, this, &ScriptManagerScriptingInterface::entityScriptDetailsUpdated);
         connect(_manager, &ScriptManager::entityScriptPreloadFinished, this, &ScriptManagerScriptingInterface::entityScriptPreloadFinished);
-        connect(_manager, &ScriptManager::unhandledException, this, &ScriptManagerScriptingInterface::unhandledException);
+        connect(_manager, &ScriptManager::unhandledException, this, &ScriptManagerScriptingInterface::scriptManagerException);
+    }
+
+    void ScriptManagerScriptingInterface::scriptManagerException(std::shared_ptr<ScriptException> exception) {
+        // V8TODO: What should we actually handle here?
+
+
+        // emit unhandledException(exception.thrownValue);
     }
\ No newline at end of file
diff --git a/libraries/script-engine/src/ScriptManagerScriptingInterface.h b/libraries/script-engine/src/ScriptManagerScriptingInterface.h
index 9806c9ae2b..76cf1cbb1f 100644
--- a/libraries/script-engine/src/ScriptManagerScriptingInterface.h
+++ b/libraries/script-engine/src/ScriptManagerScriptingInterface.h
@@ -698,7 +698,11 @@ protected:
     Q_INVOKABLE void entityScriptContentAvailable(const EntityItemID& entityID, const QString& scriptOrURL, const QString& contents, bool isURL, bool success, const QString& status)
         { _manager->entityScriptContentAvailable(entityID, scriptOrURL, contents, isURL, success, status); }
 
+private slots:
+    void scriptManagerException(std::shared_ptr<ScriptException> exception);
+
 
 private:
+
     ScriptManager *_manager;
 };
\ No newline at end of file
diff --git a/libraries/script-engine/src/v8/ScriptEngineV8.cpp b/libraries/script-engine/src/v8/ScriptEngineV8.cpp
index d9cdf09104..229524973e 100644
--- a/libraries/script-engine/src/v8/ScriptEngineV8.cpp
+++ b/libraries/script-engine/src/v8/ScriptEngineV8.cpp
@@ -71,20 +71,17 @@ bool ScriptEngineV8::IS_THREADSAFE_INVOCATION(const QThread* thread, const QStri
     return false;
 }
 
-// engine-aware JS Error copier and factory
-V8ScriptValue ScriptEngineV8::makeError(const V8ScriptValue& _other, const QString& type) {
+ScriptValue ScriptEngineV8::makeError(const ScriptValue& _other, const QString& type) {
     if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
-        v8::Locker locker(_v8Isolate);
-        v8::Isolate::Scope isolateScope(_v8Isolate);
-        v8::HandleScope handleScope(_v8Isolate);
-        v8::Context::Scope contextScope(getContext());
-        return V8ScriptValue(this, v8::Null(_v8Isolate));
+        return nullValue();
     }
     v8::Locker locker(_v8Isolate);
     v8::Isolate::Scope isolateScope(_v8Isolate);
     v8::HandleScope handleScope(_v8Isolate);
     v8::Context::Scope contextScope(getContext());
-    return V8ScriptValue(this, v8::Null(_v8Isolate));
+    return nullValue();
+}
+
     //V8TODO
     /*
     auto other = _other;
@@ -117,33 +114,8 @@ V8ScriptValue ScriptEngineV8::makeError(const V8ScriptValue& _other, const QStri
         err.setProperty(it.name(), it.value());
     }
     return err;*/
-}
+//}
 
-ScriptValue ScriptEngineV8::makeError(const ScriptValue& _other, const QString& type) {
-    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
-        return nullValue();
-    }
-    v8::Locker locker(_v8Isolate);
-    v8::Isolate::Scope isolateScope(_v8Isolate);
-    v8::HandleScope handleScope(_v8Isolate);
-    v8::Context::Scope contextScope(getContext());
-    return nullValue();
-
-    //V8TODO
-    //what does makeError actually do?
-    /*ScriptValueV8Wrapper* unwrapped = ScriptValueV8Wrapper::unwrap(_other);
-    V8ScriptValue other;
-    if (_other.isString()) {
-        other = QScriptEngine::newObject();
-        other.setProperty("message", _other.toString());
-    } else if (unwrapped) {
-        other = unwrapped->toV8Value();
-    } else {
-        other = QScriptEngine::newVariant(_other.toVariant());
-    }
-    V8ScriptValue result = makeError(other, type);
-    return ScriptValue(new ScriptValueV8Wrapper(this, std::move(result)));*/
-}
 
 // check syntax and when there are issues returns an actual "SyntaxError" with the details
 ScriptValue ScriptEngineV8::checkScriptSyntax(ScriptProgramPointer program) {
@@ -200,82 +172,14 @@ ScriptValue ScriptEngineV8::checkScriptSyntax(ScriptProgramPointer program) {
     return undefinedValue();
 }*/
 
-// this pulls from the best available information to create a detailed snapshot of the current exception
-ScriptValue ScriptEngineV8::cloneUncaughtException(const QString& extraDetail) {
-    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
-        return nullValue();
-    }
-    if (!hasUncaughtException()) {
-        return nullValue();
-    }
-    v8::Locker locker(_v8Isolate);
-    v8::Isolate::Scope isolateScope(_v8Isolate);
-    v8::HandleScope handleScope(_v8Isolate);
-    v8::Context::Scope contextScope(getContext());
-    return nullValue();
-    //V8TODO
-    /*
-    auto exception = uncaughtException();
-    // ensure the error object is engine-local
-    auto err = makeError(exception);
-
-    // not sure why Qt does't offer uncaughtExceptionFileName -- but the line number
-    // on its own is often useless/wrong if arbitrarily married to a filename.
-    // when the error object already has this info, it seems to be the most reliable
-    auto fileName = exception.property("fileName").toString();
-    auto lineNumber = exception.property("lineNumber").toInt32();
-
-    // the backtrace, on the other hand, seems most reliable taken from uncaughtExceptionBacktrace
-    auto backtrace = uncaughtExceptionBacktrace();
-    if (backtrace.isEmpty()) {
-        // fallback to the error object
-        backtrace = exception.property("stack").toString().split(ScriptManager::SCRIPT_BACKTRACE_SEP);
-    }
-    // the ad hoc "detail" property can be used now to embed additional clues
-    auto detail = exception.property("detail").toString();
-    if (detail.isEmpty()) {
-        detail = extraDetail;
-    } else if (!extraDetail.isEmpty()) {
-        detail += "(" + extraDetail + ")";
-    }
-    if (lineNumber <= 0) {
-        lineNumber = uncaughtExceptionLineNumber();
-    }
-    if (fileName.isEmpty()) {
-        // climb the stack frames looking for something useful to display
-        for (auto c = QScriptEngine::currentContext(); c && fileName.isEmpty(); c = c->parentContext()) {
-            V8ScriptContextInfo info{ c };
-            if (!info.fileName().isEmpty()) {
-                // take fileName:lineNumber as a pair
-                fileName = info.fileName();
-                lineNumber = info.lineNumber();
-                if (backtrace.isEmpty()) {
-                    backtrace = c->backtrace();
-                }
-                break;
-            }
-        }
-    }
-    err.setProperty("fileName", fileNlintame);
-    err.setProperty("lineNumber", lineNumber);
-    err.setProperty("detail", detail);
-    err.setProperty("stack", backtrace.join(ScriptManager::SCRIPT_BACKTRACE_SEP));
-
-#ifdef DEBUG_JS_EXCEPTIONS
-    err.setProperty("_fileName", exception.property("fileName").toString());
-    err.setProperty("_stack", uncaughtExceptionBacktrace().join(SCRIPT_BACKTRACE_SEP));
-    err.setProperty("_lineNumber", uncaughtExceptionLineNumber());
-#endif
-    return err;
-    */
-}
-
 bool ScriptEngineV8::raiseException(const V8ScriptValue& exception) {
     if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
         return false;
     }
     //V8TODO
-    _v8Isolate->ThrowException(makeError(exception).get());
+    // _v8Isolate->ThrowException(makeError(exception).get());
+
+
     /*if (QScriptEngine::currentContext()) {
         // we have an active context / JS stack frame so throw the exception per usual
         QScriptEngine::currentContext()->throwValue(makeError(exception));
@@ -290,22 +194,6 @@ bool ScriptEngineV8::raiseException(const V8ScriptValue& exception) {
     return false;
 }
 
-bool ScriptEngineV8::maybeEmitUncaughtException(const QString& debugHint) {
-
-    /*
-    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
-        return false;
-    }
-    if (!isEvaluating() && hasUncaughtException()) {
-        emit exception(cloneUncaughtException(debugHint));
-        clearExceptions();
-        return true;
-    }
-
-    */
-    return false;
-}
-
 // Lambda
 /*ScriptValue ScriptEngineV8::newLambdaFunction(std::function<V8ScriptValue(V8ScriptContext*, ScriptEngineV8*)> operation,
                                                  const V8ScriptValue& data,
@@ -1019,12 +907,11 @@ ScriptValue ScriptEngineV8::evaluateInClosure(const ScriptValue& _closure,
             }
 
             if (hasUncaughtException()) {
-                auto err = cloneUncaughtException(__FUNCTION__);
 #ifdef DEBUG_JS_EXCEPTIONS
                 qCWarning(shared) << __FUNCTION__ << "---------- hasCaught:" << err.toString() << result.toString();
                 err.setProperty("_result", result);
 #endif
-                result = err;
+                result = nullValue();
             } else {
                 result = ScriptValue(new ScriptValueV8Wrapper(this, V8ScriptValue(this, v8Result)));
             }
@@ -1073,34 +960,9 @@ ScriptValue ScriptEngineV8::evaluate(const QString& sourceCode, const QString& f
     v8::ScriptOrigin scriptOrigin(getIsolate(), v8::String::NewFromUtf8(getIsolate(), fileName.toStdString().c_str()).ToLocalChecked());
     v8::Local<v8::Script> script;
     if (!v8::Script::Compile(getContext(), v8::String::NewFromUtf8(getIsolate(), sourceCode.toStdString().c_str()).ToLocalChecked(), &scriptOrigin).ToLocal(&script)) {
-        //V8TODO replace this with external function
-        int errorColumnNumber = 0;
-        int errorLineNumber = 0;
-        QString errorMessage = "";
-        QString errorBacktrace = "";
-        //v8::String::Utf8Value utf8Value(getIsolate(), tryCatch.Exception());
-        v8::String::Utf8Value utf8Value(getIsolate(), tryCatch.Message()->Get());
-        errorMessage = QString(*utf8Value);
-        v8::Local<v8::Message> exceptionMessage = tryCatch.Message();
-        if (!exceptionMessage.IsEmpty()) {
-            errorLineNumber = exceptionMessage->GetLineNumber(getContext()).FromJust();
-            errorColumnNumber = exceptionMessage->GetStartColumn(getContext()).FromJust();
-            v8::Local<v8::Value> backtraceV8String;
-            if (tryCatch.StackTrace(getContext()).ToLocal(&backtraceV8String)) {
-                if (backtraceV8String->IsString()) {
-                    if (v8::Local<v8::String>::Cast(backtraceV8String)->Length() > 0) {
-                        v8::String::Utf8Value backtraceUtf8Value(getIsolate(), backtraceV8String);
-                        errorBacktrace = *backtraceUtf8Value;
-                    }
-                }
-            }
-            qCDebug(scriptengine) << "Compiling script \"" << fileName << "\" failed on line " << errorLineNumber << " column " << errorColumnNumber << " with message: \"" << errorMessage <<"\" backtrace: " << errorBacktrace;
-        }
-        auto err = makeError(newValue(errorMessage));
-        raiseException(err);
-        maybeEmitUncaughtException("compile");
+        setUncaughtException(tryCatch, "Error while compiling script");
         _evaluatingCounter--;
-        return err;
+        return nullValue();
     }
     //qCDebug(scriptengine) << "Script compilation succesful: " << fileName;
 
@@ -1145,6 +1007,12 @@ ScriptValue ScriptEngineV8::evaluate(const QString& sourceCode, const QString& f
     return ScriptValue(new ScriptValueV8Wrapper(this, std::move(resultValue)));
 }
 
+
+void ScriptEngineV8::setUncaughtEngineException(const QString &reason, const QString& info) {
+    auto ex = std::make_shared<ScriptEngineException>(reason, info);
+    setUncaughtException(ex);
+}
+
 void ScriptEngineV8::setUncaughtException(const v8::TryCatch &tryCatch, const QString& info) {
     if (!tryCatch.HasCaught()) {
         qCWarning(scriptengine) << "setUncaughtException called without exception";
@@ -1152,8 +1020,8 @@ void ScriptEngineV8::setUncaughtException(const v8::TryCatch &tryCatch, const QS
         return;
     }
 
-    ScriptException ex;
-    ex.additionalInfo = info;
+    auto ex = std::make_shared<ScriptException>();
+    ex->additionalInfo = info;
 
     v8::Locker locker(_v8Isolate);
     v8::Isolate::Scope isolateScope(_v8Isolate);
@@ -1166,30 +1034,35 @@ void ScriptEngineV8::setUncaughtException(const v8::TryCatch &tryCatch, const QS
     //v8::String::Utf8Value utf8Value(getIsolate(), tryCatch.Exception());
     v8::String::Utf8Value utf8Value(getIsolate(), tryCatch.Message()->Get());
 
-    ex.errorMessage = QString(*utf8Value);
+    ex->errorMessage = QString(*utf8Value);
 
     v8::Local<v8::Message> exceptionMessage = tryCatch.Message();
     if (!exceptionMessage.IsEmpty()) {
-        ex.errorLine = exceptionMessage->GetLineNumber(getContext()).FromJust();
-        ex.errorColumn = exceptionMessage->GetStartColumn(getContext()).FromJust();
+        ex->errorLine = exceptionMessage->GetLineNumber(getContext()).FromJust();
+        ex->errorColumn = exceptionMessage->GetStartColumn(getContext()).FromJust();
         v8::Local<v8::Value> backtraceV8String;
         if (tryCatch.StackTrace(getContext()).ToLocal(&backtraceV8String)) {
             if (backtraceV8String->IsString()) {
                 if (v8::Local<v8::String>::Cast(backtraceV8String)->Length() > 0) {
                     v8::String::Utf8Value backtraceUtf8Value(getIsolate(), backtraceV8String);
                     QString errorBacktrace = *backtraceUtf8Value;
-                    ex.backtrace = errorBacktrace.split("\n");
+                    ex->backtrace = errorBacktrace.split("\n");
 
                 }
             }
         }
     }
 
-    qCDebug(scriptengine) << "Emitting exception:" << ex;
-    _uncaughtException = ex;
-    emit exception(ex);
+    setUncaughtException(ex);
 }
 
+void ScriptEngineV8::setUncaughtException(std::shared_ptr<ScriptException> uncaughtException) {
+    qCDebug(scriptengine) << "Emitting exception:" << uncaughtException;
+    _uncaughtException = uncaughtException;
+
+    auto copy = uncaughtException->clone();
+    emit exception(copy);
+}
 
 
 QString ScriptEngineV8::formatErrorMessageFromTryCatch(v8::TryCatch &tryCatch) {
@@ -1274,18 +1147,14 @@ Q_INVOKABLE ScriptValue ScriptEngineV8::evaluate(const ScriptProgramPointer& pro
         v8::Context::Scope contextScope(getContext());
         ScriptProgramV8Wrapper* unwrapped = ScriptProgramV8Wrapper::unwrap(program);
         if (!unwrapped) {
-            errorValue = makeError(newValue("could not unwrap program"));
-            raiseException(errorValue);
-            maybeEmitUncaughtException("compile");
+            setUncaughtEngineException("Could not unwrap program", "Compile error");
             hasFailed = true;
         }
 
         if(!hasFailed) {
             ScriptSyntaxCheckResultPointer syntaxCheck = unwrapped->checkSyntax();
             if (syntaxCheck->state() == ScriptSyntaxCheckResult::Error) {
-                errorValue = makeError(newValue(syntaxCheck->errorMessage()));
-                raiseException(errorValue);
-                maybeEmitUncaughtException("compile");
+                setUncaughtEngineException(syntaxCheck->errorMessage(), "Compile error");
                 hasFailed = true;
             }
         }
@@ -1307,8 +1176,7 @@ Q_INVOKABLE ScriptValue ScriptEngineV8::evaluate(const ScriptProgramPointer& pro
                 Q_ASSERT(tryCatchRun.HasCaught());
                 auto runError = tryCatchRun.Message();
                 errorValue = ScriptValue(new ScriptValueV8Wrapper(this, V8ScriptValue(this, runError->Get())));
-                raiseException(errorValue);
-                maybeEmitUncaughtException("evaluate");
+                raiseException(errorValue, "evaluation error");
                 hasFailed = true;
             } else {
                 // V8TODO this is just to check if run will always return false for uncaught exception
@@ -1529,7 +1397,7 @@ void ScriptEngineV8::abortEvaluation() {
 }
 
 void ScriptEngineV8::clearExceptions() {
-    _uncaughtException = ScriptException();
+    _uncaughtException.reset();
 }
 
 ScriptContext* ScriptEngineV8::currentContext() const {
@@ -1551,7 +1419,7 @@ ScriptContext* ScriptEngineV8::currentContext() const {
 }
 
 bool ScriptEngineV8::hasUncaughtException() const {
-    return !_uncaughtException.isEmpty();
+    return _uncaughtException != nullptr;
 }
 
 bool ScriptEngineV8::isEvaluating() const {
@@ -1667,11 +1535,15 @@ void ScriptEngineV8::setThread(QThread* thread) {
 }*/
 
 
-ScriptException ScriptEngineV8::uncaughtException() const {
-    return _uncaughtException;
+std::shared_ptr<ScriptException> ScriptEngineV8::uncaughtException() const {
+    return _uncaughtException->clone();
 }
 
-bool ScriptEngineV8::raiseException(const ScriptValue& exception) {
+bool ScriptEngineV8::raiseException(const QString& error, const QString &reason) {
+    return raiseException(ScriptValue(), reason);
+}
+
+bool ScriptEngineV8::raiseException(const ScriptValue& exception, const QString &reason) {
     //V8TODO
     //Q_ASSERT(false);
 //    qCritical() << "Script exception occurred: " << exception.toString();
@@ -1681,6 +1553,7 @@ bool ScriptEngineV8::raiseException(const ScriptValue& exception) {
   //  emit
     //return raiseException(qException);
 
+    qCCritical(scriptengine) << "Raise exception for reason" << reason << "NOT IMPLEMENTED!";
     return false;
 }
 
diff --git a/libraries/script-engine/src/v8/ScriptEngineV8.h b/libraries/script-engine/src/v8/ScriptEngineV8.h
index b02a73a552..7387df80b4 100644
--- a/libraries/script-engine/src/v8/ScriptEngineV8.h
+++ b/libraries/script-engine/src/v8/ScriptEngineV8.h
@@ -71,7 +71,6 @@ public:  // construction
 public:  // ScriptEngine implementation
     virtual void abortEvaluation() override;
     virtual void clearExceptions() override;
-    virtual ScriptValue cloneUncaughtException(const QString& detail = QString()) override;
     virtual ScriptContext* currentContext() const override;
     Q_INVOKABLE virtual ScriptValue evaluate(const QString& program, const QString& fileName = QString()) override;
     Q_INVOKABLE virtual ScriptValue evaluate(const ScriptProgramPointer& program) override;
@@ -81,11 +80,6 @@ public:  // ScriptEngine implementation
     virtual bool isEvaluating() const override;
     //virtual ScriptValue lintScript(const QString& sourceCode, const QString& fileName, const int lineNumber = 1) override;
     virtual ScriptValue checkScriptSyntax(ScriptProgramPointer program) override;
-    virtual ScriptValue makeError(const ScriptValue& other, const QString& type = "Error") override;
-
-
-    // if there is a pending exception and we are at the top level (non-recursive) stack frame, this emits and resets it
-    virtual bool maybeEmitUncaughtException(const QString& debugHint = QString()) override;
 
     virtual ScriptValue newArray(uint length = 0) override;
     virtual ScriptValue newArrayBuffer(const QByteArray& message) override;
@@ -106,7 +100,11 @@ public:  // ScriptEngine implementation
     virtual ScriptValue newValue(const char* value) override;
     virtual ScriptValue newVariant(const QVariant& value) override;
     virtual ScriptValue nullValue() override;
-    virtual bool raiseException(const ScriptValue& exception) override;
+
+    virtual ScriptValue makeError(const ScriptValue& other, const QString& type = "Error") override;
+
+    virtual bool raiseException(const QString& exception, const QString &reason = QString()) override;
+    virtual bool raiseException(const ScriptValue& exception, const QString &reason = QString()) override;
     Q_INVOKABLE virtual void registerEnum(const QString& enumName, QMetaEnum newEnum) override;
     Q_INVOKABLE virtual void registerFunction(const QString& name,
                                               ScriptEngine::FunctionSignature fun,
@@ -128,7 +126,7 @@ public:  // ScriptEngine implementation
     virtual void setThread(QThread* thread) override;
     //Q_INVOKABLE virtual void enterIsolateOnThisThread() override;
     virtual ScriptValue undefinedValue() override;
-    virtual ScriptException uncaughtException() const override;
+    virtual std::shared_ptr<ScriptException> uncaughtException() const override;
     virtual void updateMemoryCost(const qint64& deltaSize) override;
     virtual void requestCollectGarbage() override { while(!_v8Isolate->IdleNotificationDeadline(getV8Platform()->MonotonicallyIncreasingTime() + GARBAGE_COLLECTION_TIME_LIMIT_S)) {}; }
     virtual void compileTest() override;
@@ -142,7 +140,7 @@ public:  // ScriptEngine implementation
     inline bool IS_THREADSAFE_INVOCATION(const QString& method) { return ScriptEngine::IS_THREADSAFE_INVOCATION(method); }
 
 protected: // brought over from BaseScriptEngine
-    V8ScriptValue makeError(const V8ScriptValue& other, const QString& type = "Error");
+
 
     // if the currentContext() is valid then throw the passed exception; otherwise, immediately emit it.
     // note: this is used in cases where C++ code might call into JS API methods directly
@@ -223,16 +221,18 @@ signals:
      *
      * @param exception Exception that was thrown
      */
-    void exception(const ScriptException &exception);
+    void exception(std::shared_ptr<ScriptException> exception);
 
 protected:
     static QMutex _v8InitMutex;
     static std::once_flag _v8InitOnceFlag;
     static v8::Platform* getV8Platform();
 
+    void setUncaughtEngineException(const QString &message, const QString& info = QString());
     void setUncaughtException(const v8::TryCatch &tryCatch, const QString& info = QString());
+    void setUncaughtException(std::shared_ptr<ScriptException> exception);
 
-    ScriptException _uncaughtException;
+    std::shared_ptr<ScriptException> _uncaughtException;
 
 
     // V8TODO: clean up isolate when script engine is destroyed?
diff --git a/tests/script-engine/src/tests/010_exception.js b/tests/script-engine/src/tests/010_exception.js
new file mode 100644
index 0000000000..a280f9a5cc
--- /dev/null
+++ b/tests/script-engine/src/tests/010_exception.js
@@ -0,0 +1 @@
+foo();