XCODE INTERNAL ERROR

ASSERTION FAILURE in /SourceCache/IDEInterfaceBuilderCocoaTouch/IDEInterfaceBuilderCocoaTouch-933/IBPlugin/Utilities/IBObjectMarshalling.m:179
Details:  Interface Builder encountered an error communicating with the iOS Simulator. "Interface Builder Cocoa Touch Tool" (2425) failed to launch and exited with status (null), signal 10. Please check Console.app for crash reports for "Interface Builder Cocoa Touch Tool" for further information.
Function: NSDistantObject<IBCocoaTouchToolProtocol> *IBAttachToCocoaTouchTool(IBCocoaTouchTargetRuntime *)
Thread:   <NSThread: 0x40010a260>{name = (null), num = 1}
Hints:   None
Backtrace:
  0  0x00000001056ca5a1 -[IDEAssertionHandler handleFailureInFunction:fileName:lineNumber:messageFormat:arguments:] (in IDEKit)
  1  0x0000000104d34774 _DVTAssertionHandler (in DVTFoundation)
  2  0x0000000104d461a4 _DVTAssertionFailureHandler (in DVTFoundation)
  3  0x0000000108a6af90 IBAttachToCocoaTouchTool (in IDEInterfaceBuilderCocoaTouchIntegration)
  4  0x0000000108a6ab48 (in IDEInterfaceBuilderCocoaTouchIntegration)
  5  0x0000000108a6a9a9 IBAskClassInTargetRuntimeForValueForKeyPathUsingResultMarshallerWithContext (in IDEInterfaceBuilderCocoaTouchIntegration)
  6  0x0000000108a6a49d (in IDEInterfaceBuilderCocoaTouchIntegration)
  7  0x0000000108a6a15d (in IDEInterfaceBuilderCocoaTouchIntegration)
  8  0x0000000107dc159a -[IBTargetRuntime installColorListIfNeeded] (in IDEInterfaceBuilderKit)
  9  0x0000000108a940f9 (in IDEInterfaceBuilderCocoaTouchIntegration)
 10  0x0000000108a940a2 (in IDEInterfaceBuilderCocoaTouchIntegration)
 11  0x0000000107dfa9a6 -[IBAbstractDocumentEditor viewDidInstall] (in IDEInterfaceBuilderKit)
 12  0x0000000104ef898e -[DVTControllerContentView _viewDidInstall] (in DVTKit)
 13  0x0000000104ef83fd -[DVTControllerContentView viewDidMoveToWindow] (in DVTKit)
 14  0x00007fff91f7f153 -[NSView _setWindow:] (in AppKit)
 15  0x00007fff91f7d3e2 -[NSView addSubview:] (in AppKit)
 16  0x00000001087515b4 -[NSView(IBAppKitViewIntegration) ibSwizzledNSViewDebug_addSubview:] (in IDEInterfaceBuilderCocoaIntegration)
 17  0x00007fff92015e44 -[NSView setSubviews:] (in AppKit)
 18  0x0000000104efe980 -[DVTBorderedView setContentView:] (in DVTKit)
 19  0x00000001055ef710 -[IDEEditorContext _setEditorView] (in IDEKit)
 20  0x00000001055fa59a -[IDEEditorContext setEditor:] (in IDEKit)
 21  0x00007fff8b36bd1a _NSSetObjectValueAndNotify (in Foundation)
 22  0x00000001055f9b9c __66-[IDEEditorContext _openNavigableItem:documentExtension:document:]_block_invoke_0 (in IDEKit)
 23  0x00000001055f9764 -[IDEEditorContext _performBlockInsideReentrantGuard:] (in IDEKit)
 24  0x00000001055f95b3 -[IDEEditorContext _openNavigableItem:documentExtension:document:] (in IDEKit)
 25  0x00000001056aa42c -[IDEEditorContext _openNavigableItem:withContentsOfURL:] (in IDEKit)
 26  0x00000001056ac0d6 -[IDEEditorContext _notifyDelegateAndOpenNavigableItem:withContentsURL:documentExtensionIdentifier:locationToSelect:annotationRepresentedObject:stateDictionary:annotationWantsIndicatorAnimation:exploreAnnotationRepresentedObject:] (in IDEKit)
 27  0x00000001056251ab -[IDEEditorContext _notifyDelegateAndOpenEditorOpenSpecifier:updateHistory:] (in IDEKit)
 28  0x0000000105624f19 -[IDEEditorContext _openEditorOpenSpecifier:updateHistory:] (in IDEKit)
 29  0x0000000105624c38 -[IDEEditorContext openEditorOpenSpecifier:] (in IDEKit)
 30  0x0000000105624c19 -[IDEEditorModeViewController openEditorOpenSpecifier:editorContext:] (in IDEKit)
 31  0x0000000105624bd6 -[IDEEditorArea _openEditorOpenSpecifier:editorContext:takeFocus:] (in IDEKit)
 32  0x00000001056bfeb7 __108+[IDEEditorCoordinator _doOpenEditorOpenSpecifier:forWorkspaceTabController:editorContext:target:takeFocus:]_block_invoke_0 (in IDEKit)
 33  0x0000000105624904 +[IDEEditorCoordinator _doOpenWithWorkspaceTabController:editorContext:target:allowFallback:documentURL:usingBlock:] (in IDEKit)
 34  0x00000001056bfdd5 +[IDEEditorCoordinator _doOpenEditorOpenSpecifier:forWorkspaceTabController:editorContext:target:takeFocus:] (in IDEKit)
 35  0x0000000105624353 -[_IDEOpenRequest _runIfNecessary] (in IDEKit)
 36  0x00007fff8b30e25a __NSFireDelayedPerform (in Foundation)
 37  0x00007fff8e8c6f84 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ (in CoreFoundation)
 38  0x00007fff8e8c6ad6 __CFRunLoopDoTimer (in CoreFoundation)
 39  0x00007fff8e8a7471 __CFRunLoopRun (in CoreFoundation)
 40  0x00007fff8e8a6ae6 CFRunLoopRunSpecific (in CoreFoundation)
 41  0x00007fff957473d3 RunCurrentEventLoopInMode (in HIToolbox)
 42  0x00007fff9574e63d ReceiveNextEventCommon (in HIToolbox)
 43  0x00007fff9574e4ca BlockUntilNextEventMatchingListInMode (in HIToolbox)
 44  0x00007fff91e6b3f1 _DPSNextEvent (in AppKit)
 45  0x00007fff91e6acf5 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] (in AppKit)
 46  0x00007fff91e6762d -[NSApplication run] (in AppKit)
 47  0x00007fff920e680c NSApplicationMain (in AppKit)
 48  0x0000000104ccaeec (in Xcode)
 49  0x0000000000000002