diff --git a/arangod/Aql/Query.cpp b/arangod/Aql/Query.cpp
index 893c254cf7..820cfe26cd 100644
--- a/arangod/Aql/Query.cpp
+++ b/arangod/Aql/Query.cpp
@@ -67,12 +67,14 @@ static std::string StateNames[] = {
     "instantiating plan",  // PLAN_INSTANTIATION
     "optimizing plan",     // PLAN_OPTIMIZATION
     "executing",           // EXECUTION
-    "finalizing"           // FINALIZATION
+    "finalizing",          // FINALIZATION
+
+    "invalid"              // INVALID
 };
 
 // make sure the state strings and the actual states match
 static_assert(sizeof(StateNames) / sizeof(std::string) ==
-                  static_cast<size_t>(ExecutionState::INVALID_STATE),
+                  static_cast<size_t>(ExecutionState::INVALID_STATE) + 1,
               "invalid number of ExecutionState values");
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/arangod/RestHandler/RestCursorHandler.cpp b/arangod/RestHandler/RestCursorHandler.cpp
index 4efdccb125..e5846bc702 100644
--- a/arangod/RestHandler/RestCursorHandler.cpp
+++ b/arangod/RestHandler/RestCursorHandler.cpp
@@ -201,7 +201,6 @@ void RestCursorHandler::processQuery(VPackSlice const& slice) {
     }
     arangodb::JsonCursor* cursor = cursors->createFromVelocyPack(
         builder, batchSize, extra, ttl, count, queryResult.cached);
-    queryResult.json = nullptr;
 
     try {
       _response->body().appendChar('{');
diff --git a/arangod/VocBase/replication-applier.cpp b/arangod/VocBase/replication-applier.cpp
index a2d5d50f92..08a610ccd3 100644
--- a/arangod/VocBase/replication-applier.cpp
+++ b/arangod/VocBase/replication-applier.cpp
@@ -1469,7 +1469,7 @@ void TRI_replication_applier_t::toVelocyPack(VPackBuilder& builder) const {
   // add server info
   builder.add("server", VPackValue(VPackValueType::Object));
   builder.add("version", VPackValue(TRI_VERSION));
-  builder.add("serverId", VPackValue(TRI_StringUInt64(TRI_GetIdServer())));
+  builder.add("serverId", VPackValue(std::to_string(TRI_GetIdServer())));
   builder.close();  // server
 
   if (config._endpoint != nullptr) {
diff --git a/js/client/modules/@arangodb/testing.js b/js/client/modules/@arangodb/testing.js
index 7a09d8d71f..23b7dba3df 100644
--- a/js/client/modules/@arangodb/testing.js
+++ b/js/client/modules/@arangodb/testing.js
@@ -329,6 +329,10 @@ function readImportantLogLines(logPath) {
 /// # and know the PID plus the process name for later use.
 /// kernel.core_uses_pid = 1
 /// kernel.core_pattern =  /var/tmp/core-%e-%p-%t
+///
+/// If you set coreDirectory to empty, this behavior is changed: The core file
+/// expected to be named simply "core" and should exist in the current
+/// directory.
 ////////////////////////////////////////////////////////////////////////////////
 
 function analyzeCoreDump(instanceInfo, options, storeArangodPath, pid) {
@@ -340,7 +344,12 @@ function analyzeCoreDump(instanceInfo, options, storeArangodPath, pid) {
   command += "echo quit;";
   command += "sleep 2";
   command += ") | gdb " + storeArangodPath + " ";
-  command += options.coreDirectory + "/*core*" + pid + '*';
+
+  if (options.coreDirectory === "") {
+    command += "core";
+  } else {
+    command += options.coreDirectory + "/*core*" + pid + '*';
+  }
 
   const args = ['-c', command];
   print(JSON.stringify(args));
@@ -408,9 +417,12 @@ function checkInstanceAliveSingleServer(instanceInfo, options) {
       print("Core dump written; copying arangod to " +
         instanceInfo.tmpDataDir + " for later analysis.");
 
+      let corePath = (options.coreDirectory === "") ?
+        "core" :
+        options.coreDirectory + "/core*" + instanceInfo.pid.pid + "*'";
+
       res.gdbHint = "Run debugger with 'gdb " +
-        storeArangodPath + " " + options.coreDirectory +
-        "/core*" + instanceInfo.pid.pid + "*'";
+        storeArangodPath + " " + corePath;
 
       if (require("internal").platform.substr(0, 3) === 'win') {
         // Windows: wait for procdump to do its job...
diff --git a/lib/Basics/Exceptions.cpp b/lib/Basics/Exceptions.cpp
index 817491a4f3..9cad09e8e9 100644
--- a/lib/Basics/Exceptions.cpp
+++ b/lib/Basics/Exceptions.cpp
@@ -46,17 +46,36 @@ Exception::Exception(int code, char const* file, int line)
       _file(file),
       _line(line),
       _code(code) {
-#ifdef TRI_ENABLE_MAINTAINER_MODE
-#if HAVE_BACKTRACE
-  if (WithBackTrace) {
-    _errorMessage += std::string("\n\n");
-    TRI_GetBacktrace(_errorMessage);
-    _errorMessage += std::string("\n\n");
-  }
-#endif
-#endif
+  
+  appendLocation();
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief constructor, for creating an exception with an already created
+/// error message (normally based on error templates containing %s, %d etc.)
+////////////////////////////////////////////////////////////////////////////////
+
+Exception::Exception(int code, std::string const& errorMessage,
+                     char const* file, int line)
+    : _errorMessage(errorMessage), _file(file), _line(line), _code(code) {
+
+  appendLocation();
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief constructor, for creating an exception with an already created
+/// error message (normally based on error templates containing %s, %d etc.)
+////////////////////////////////////////////////////////////////////////////////
+
+Exception::Exception(int code, char const* errorMessage, char const* file,
+                     int line)
+    : _errorMessage(errorMessage), _file(file), _line(line), _code(code) {
+  
+  appendLocation();
+}
+
+Exception::~Exception() throw() {}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief returns the error message
 ////////////////////////////////////////////////////////////////////////////////
@@ -75,52 +94,32 @@ int Exception::code() const throw() { return _code; }
 
 void Exception::addToMessage(std::string const& more) { _errorMessage += more; }
 
-////////////////////////////////////////////////////////////////////////////////
-/// @brief constructor, for creating an exception with an already created
-/// error message (normally based on error templates containing %s, %d etc.)
-////////////////////////////////////////////////////////////////////////////////
-
-Exception::Exception(int code, std::string const& errorMessage,
-                     char const* file, int line)
-    : _errorMessage(errorMessage), _file(file), _line(line), _code(code) {
-#ifdef TRI_ENABLE_MAINTAINER_MODE
-#if HAVE_BACKTRACE
-  if (WithBackTrace) {
-    _errorMessage += std::string("\n\n");
-    TRI_GetBacktrace(_errorMessage);
-    _errorMessage += std::string("\n\n");
-  }
-#endif
-#endif
-}
-
-////////////////////////////////////////////////////////////////////////////////
-/// @brief constructor, for creating an exception with an already created
-/// error message (normally based on error templates containing %s, %d etc.)
-////////////////////////////////////////////////////////////////////////////////
-
-Exception::Exception(int code, char const* errorMessage, char const* file,
-                     int line)
-    : _errorMessage(errorMessage), _file(file), _line(line), _code(code) {
-#ifdef TRI_ENABLE_MAINTAINER_MODE
-#if HAVE_BACKTRACE
-  if (WithBackTrace) {
-    _errorMessage += std::string("\n\n");
-    TRI_GetBacktrace(_errorMessage);
-    _errorMessage += std::string("\n\n");
-  }
-#endif
-#endif
-}
-
-Exception::~Exception() throw() {}
-
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief return exception message
 ////////////////////////////////////////////////////////////////////////////////
 
 char const* Exception::what() const throw() { return _errorMessage.c_str(); }
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief append original error location to message
+////////////////////////////////////////////////////////////////////////////////
+
+void Exception::appendLocation () {
+  if (_code == TRI_ERROR_INTERNAL) {
+    _errorMessage += std::string(" (location: ") + _file + ":" + std::to_string(_line) + "). Please report this error to arangodb.com";
+  }
+
+#ifdef TRI_ENABLE_MAINTAINER_MODE
+#if HAVE_BACKTRACE
+  if (WithBackTrace) {
+    _errorMessage += std::string("\n\n");
+    TRI_GetBacktrace(_errorMessage);
+    _errorMessage += std::string("\n\n");
+  }
+#endif
+#endif
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief construct an error message from a template string
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/lib/Basics/Exceptions.h b/lib/Basics/Exceptions.h
index 10e772f248..c8eac8cb3d 100644
--- a/lib/Basics/Exceptions.h
+++ b/lib/Basics/Exceptions.h
@@ -100,6 +100,8 @@ class Exception : public virtual std::exception {
   std::string message() const throw();
   int code() const throw();
   void addToMessage(std::string const&);
+ private:
+  void appendLocation ();
 
  protected:
   std::string _errorMessage;