Unreal 4.2.1 - MIDI Device Error CallBack

SIGSEGV: invalid attempt to access memory at address 0xb8

EngineCrashHandler(FGenericCrashContext const&) [in UE4Editor) + 15
, line 840958720] [in UE4Editor]
PlatformCrashHandler(int, __siginfo*, void*) [in UE4Editor-Core.dylib) + 95
, line 840958720] [in UE4Editor-Core.dylib]
_sigtramp() Address = 0x9983a5aa (filename not found) [in libsystem_platform.dylib]

FPhysCommandHandler::Flush() Address = 0x10a7e77b (filename not found) [in UE4Editor-Engine.dylib]
UWorld::Tick(ELevelTick, float) Address = 0x101523a5 (filename not found) [in UE4Editor-Engine.dylib]
FLiveEditorManager::Tick(float) Address = 0x3089c5c1 (filename not found) [in UE4Editor-LiveEditor.dylib]
UEditorEngine::Tick(float, bool) Address = 0x1477db68 (filename not found) [in UE4Editor-UnrealEd.dylib]
UUnrealEdEngine::Tick(float, bool) Address = 0x14b281f2 (filename not found) [in UE4Editor-UnrealEd.dylib]
FEngineLoop::Tick() Address = 0xe92a1dd  (filename not found) [in UE4Editor]
GuardedMain(wchar_t const*) Address = 0xe92c2e1  (filename not found) [in UE4Editor]
-[UE4AppDelegate applicationDidFinishLaunching:] Address = 0xe932630  (filename not found) [in UE4Editor]
__CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__() Address = 0x95ca8e0c (filename not found) [in CoreFoundation]
_CFXNotificationPost() Address = 0x95b9c8dd (filename not found) [in CoreFoundation]
-[NSNotificationCenter postNotificationName:object:userInfo:] Address = 0x9484a7ba (filename not found) [in Foundation]
-[NSApplication _postDidFinishNotification] Address = 0x9a54ab89 (filename not found) [in AppKit]
-[NSApplication _sendFinishLaunchingNotification] Address = 0x9a54a8bc (filename not found) [in AppKit]
-[NSApplication(NSAppleEventHandling) _handleAEOpenDocumentsForURLs:] Address = 0x9a8e0a1b (filename not found) [in AppKit]
-[NSApplication(NSAppleEventHandling) _handleCoreEvent:withReplyEvent:] Address = 0x9a5472cb (filename not found) [in AppKit]
-[NSAppleEventManager dispatchRawAppleEvent:withRawReply:handlerRefCon:] Address = 0x94868f0a (filename not found) [in Foundation]
_NSAppleEventManagerGenericHandler() Address = 0x94868d7d (filename not found) [in Foundation]
aeDispatchAppleEvent(AEDesc const*, AEDesc*, unsigned int, unsigned char*) Address = 0x99292e1f (filename not found) [in AE]
dispatchEventAndSendReply(AEDesc const*, AEDesc*) Address = 0x99292c32 (filename not found) [in AE]
aeProcessAppleEvent() Address = 0x99292b36 (filename not found) [in AE]
AEProcessAppleEvent() Address = 0x986b3161 (filename not found) [in HIToolbox]
_DPSNextEvent() Address = 0x9a5430d6 (filename not found) [in AppKit]
-[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] Address = 0x9a5428bb (filename not found) [in AppKit]
-[NSApplication run] Address = 0x9a5369bc (filename not found) [in AppKit]
NSApplicationMain() Address = 0x9a5217a3 (filename not found) [in AppKit]
tchar_main(int, wchar_t**) Address = 0xe932e9b  (filename not found) [in UE4Editor]
main() Address = 0xe932904  (filename not found) [in UE4Editor]
start() Address = 0x9640e5fd (filename not found) [in libdyld.dylib]