XCODE ERROR

ASSERTION FAILURE in /SourceCache/IDEInterfaceBuilderCocoaTouch/IDEInterfaceBuilderCocoaTouch-534/IBPlugin/Utilities/IBObjectMarshalling.m:152
Details:  Interface Builder encountered an error communicating with the iOS Simulator. "Interface Builder Cocoa Touch Tool" (4130) failed to launch and exited with status (null), signal 5. 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  0x0000000103c41152 -[IDEAssertionHandler handleFailureInFunction:fileName:lineNumber:messageFormat:arguments:] (in IDEKit)
  1  0x00000001032d91bc _DVTAssertionHandler (in DVTFoundation)
  2  0x00000001032e9304 _DVTAssertionFailureHandler (in DVTFoundation)
  3  0x0000000106a5c2bd IBAttachToCocoaTouchTool (in IDEInterfaceBuilderCocoaTouchIntegration)
  4  0x0000000106a5be87 (in IDEInterfaceBuilderCocoaTouchIntegration)
  5  0x0000000106a5bd4c IBAskClassInTargetRuntimeForValueForKeyPathUsingResultMarshallerWithContext (in IDEInterfaceBuilderCocoaTouchIntegration)
  6  0x0000000106a5b877 (in IDEInterfaceBuilderCocoaTouchIntegration)
  7  0x0000000106a7b219 (in IDEInterfaceBuilderCocoaTouchIntegration)
  8  0x0000000106a7b25a (in IDEInterfaceBuilderCocoaTouchIntegration)
  9  0x0000000106a80148 (in IDEInterfaceBuilderCocoaTouchIntegration)
 10  0x00000001063adcee -[NSView(IBViewIntegration) ibWarnings:forDocument:withComputationContext:] (in IDEInterfaceBuilderKit)
 11  0x0000000106772a76 -[NSView(IBAppKitViewIntegration) ibSwizzledNSViewWarnings:forDocument:withComputationContext:] (in IDEInterfaceBuilderCocoaIntegration)
 12  0x0000000106a98431 (in IDEInterfaceBuilderCocoaTouchIntegration)
 13  0x0000000106a9f2c3 (in IDEInterfaceBuilderCocoaTouchIntegration)
 14  0x0000000106ab70f9 (in IDEInterfaceBuilderCocoaTouchIntegration)
 15  0x000000010635b0ca -[IBDocument rebuildWarnings] (in IDEInterfaceBuilderKit)
 16  0x000000010635b2d7 -[IBDocument warnings] (in IDEInterfaceBuilderKit)
 17  0x00000001063fa8d6 -[IBIssueProvider updateWarningsForOpenDocument:filePath:] (in IDEInterfaceBuilderKit)
 18  0x000000010633fd89 -[IBIssueProvider updateOpenDocuments] (in IDEInterfaceBuilderKit)
 19  0x00007fff8931d18a NSKeyValueNotifyObserver (in Foundation)
 20  0x00007fff8933e387 NSKeyValueDidChange (in Foundation)
 21  0x00007fff892eaa2f -[NSObject(NSKeyValueObserverNotification) didChangeValueForKey:] (in Foundation)
 22  0x0000000103b85a87 -[IDEDocumentController addDocument:] (in IDEKit)
 23  0x0000000103ba9a36 +[IDEDocumentController retainEditorDocument:] (in IDEKit)
 24  0x0000000103ba8c0d +[IDEDocumentController _retainedNewEditorDocumentWithClass:ofURL:ofType:extension:error:] (in IDEKit)
 25  0x0000000103ba8915 -[IDEEditorContext _newEditorDocumentWithClass:ofURL:ofType:extension:] (in IDEKit)
 26  0x0000000103ba8478 -[IDEEditorContext _openNavigableItem:documentExtension:] (in IDEKit)
 27  0x0000000103b777cc -[IDEEditorContext _openNavigableItem:] (in IDEKit)
 28  0x0000000103ba7860 -[IDEEditorContext _notifyDelegateAndOpenNavigableItem:documentExtensionIdentifier:locationToSelect:annotationRepresentedObject:stateDictionary:annotationWantsIndicatorAnimation:exploreAnnotationRepresentedObject:] (in IDEKit)
 29  0x0000000103ba3f22 -[IDEEditorContext _notifyDelegateAndOpenEditorOpenSpecifier:updateHistory:] (in IDEKit)
 30  0x0000000103ba3cb0 -[IDEEditorContext _openEditorOpenSpecifier:updateHistory:] (in IDEKit)
 31  0x0000000103ba39db -[IDEEditorContext openEditorOpenSpecifier:] (in IDEKit)
 32  0x0000000103ba39b4 -[IDEEditorModeViewController openEditorOpenSpecifier:editorContext:] (in IDEKit)
 33  0x0000000103ba3971 -[IDEEditorArea _openEditorOpenSpecifier:editorContext:takeFocus:] (in IDEKit)
 34  0x0000000103c384af __108+[IDEEditorCoordinator _doOpenEditorOpenSpecifier:forWorkspaceTabController:editorContext:target:takeFocus:]_block_invoke_0 (in IDEKit)
 35  0x0000000103c378ca __94+[IDEEditorCoordinator _doOpenIn_NewWindow_withWorkspaceTabController:documentURL:usingBlock:]_block_invoke_0 (in IDEKit)
 36  0x0000000103c3c347 -[IDEEditorArea setEditorMode:completionBlock:] (in IDEKit)
 37  0x0000000103c49b5f -[IDEWorkspaceWindowController _revertForNewWindowWithTabStateContext:documentURL:simpleEditorWindowLayout:completionBlock:] (in IDEKit)
 38  0x0000000103c18ebc -[IDEWorkspaceDocument _makeTabbedWindowControllerWithStateFromTabController:documentURL:simpleEditorWindowLayout:frontmost:completionBlock:] (in IDEKit)
 39  0x0000000103c377f3 +[IDEEditorCoordinator _doOpenIn_NewWindow_withWorkspaceTabController:documentURL:usingBlock:] (in IDEKit)
 40  0x0000000103c38270 +[IDEEditorCoordinator _doOpenIn_SeparateWindow_withWorkspaceTabController:documentURL:usingBlock:] (in IDEKit)
 41  0x0000000103ba3778 +[IDEEditorCoordinator _doOpenWithWorkspaceTabController:editorContext:target:allowFallback:documentURL:usingBlock:] (in IDEKit)
 42  0x0000000103c383d6 +[IDEEditorCoordinator _doOpenEditorOpenSpecifier:forWorkspaceTabController:editorContext:target:takeFocus:] (in IDEKit)
 43  0x0000000103ba315e -[_IDEOpenRequest _runIfNecessary] (in IDEKit)
 44  0x0000000103ba2b7a -[_IDEOpenRequest _enqueueForEventBehavior:] (in IDEKit)
 45  0x0000000103ba26b2 +[IDEEditorCoordinator _openRequestForEditorOpenSpecifier:workspaceTabController:editorContext:eventBehavior:takeFocus:] (in IDEKit)
 46  0x0000000103ba260b __99+[IDEEditorCoordinator _openEditorOpenSpecifier:forWorkspaceTabController:eventBehavior:takeFocus:]_block_invoke_0 (in IDEKit)
 47  0x0000000103ba25a0 _performBlockInsideReentrantGuard (in IDEKit)
 48  0x0000000103ba2514 +[IDEEditorCoordinator _openEditorOpenSpecifier:forWorkspaceTabController:eventBehavior:takeFocus:] (in IDEKit)
 49  0x0000000103ba2208 +[IDEEditorCoordinator openEditorOpenSpecifier:forWorkspaceTabController:eventType:] (in IDEKit)
 50  0x0000000103ba1862 -[IDEOutlineBasedNavigator _openNavigableItem:eventType:] (in IDEKit)
 51  0x00007fff8cbb911d -[NSObject performSelector:withObject:] (in CoreFoundation)
 52  0x00007fff8b3e1852 -[NSApplication sendAction:to:from:] (in AppKit)
 53  0x0000000103470222 -[DVTApplication sendAction:to:from:] (in DVTKit)
 54  0x0000000103b4fca2 -[IDEApplication sendAction:to:from:] (in IDEKit)
 55  0x00007fff8b3e1784 -[NSControl sendAction:to:] (in AppKit)
 56  0x0000000103ba165f -[IDENavigatorOutlineView sendAction:to:] (in IDEKit)
 57  0x00007fff8b447ae6 -[NSTableView _sendAction:to:row:column:] (in AppKit)
 58  0x00007fff8b4448a9 -[NSTableView mouseDown:] (in AppKit)
 59  0x00007fff8b7c126e -[NSOutlineView mouseDown:] (in AppKit)
 60  0x0000000103ba01f3 -[IDENavigatorOutlineView mouseDown:] (in IDEKit)
 61  0x00007fff8b3aa66e -[NSWindow sendEvent:] (in AppKit)
 62  0x00007fff8b342f19 -[NSApplication sendEvent:] (in AppKit)
 63  0x0000000103b4f9f6 -[IDEApplication sendEvent:] (in IDEKit)
 64  0x00007fff8b2d942b -[NSApplication run] (in AppKit)
 65  0x00007fff8b55752a NSApplicationMain (in AppKit)
 66  0x0000000103276eec (in Xcode)