swift:无法与Interface Builder通信

我刚刚在xcode 6 beta中打开了现有项目.但它崩溃了以下错误消息.

dyld: problem loading iOS simulator dyld
2014-06-05 11:15:06.604 ibtoold[952:507] Init failed: Error Domain=IBMessageChannelErrorDomain Code=1 "Failed to communicate with Interface Builder" UserInfo=0x7fd09861dbf0 {NSLocalizedDescription=Failed to communicate with Interface Builder, NSLocalizedFailureReason=Interface Builder Cocoa Touch Tool crashed: EXC_BREAKPOINT (SIGTRAP), IBCrashLog=

Dyld Error Message:
  problem loading iOS simulator dyld
}
2014-06-05 11:15:06.605 ibtoold[952:507] [MT] DVTAssertions: Warning in /SourceCache/IDEInterfaceBuilder/IDEInterfaceBuilder-6154.17/InterfaceBuilderKit/Utilities/IBAbstractMessageChannelInterfaceBuilderToolManager.m:76
Details:  Failed to attach to Interface Builder Cocoa Touch Tool with error: Error Domain=com.apple.InterfaceBuilder Code=-1 "Encountered an error communicating with Interface Builder Cocoa Touch Tool." UserInfo=0x7fd09b3a1360 {NSUnderlyingError=0x7fd09861d710 "Failed to communicate with Interface Builder", NSLocalizedDescription=Encountered an error communicating with Interface Builder Cocoa Touch Tool., NSLocalizedRecoverySuggestion=Please check Console.app for crash reports for "Interface Builder Cocoa Touch Tool" for further information., NSLocalizedFailureReason=Interface Builder Cocoa Touch Tool (962) failed to launch and exited with status (null), signal 5.



Dyld Error Message:
  problem loading iOS simulator dyld
}
Object:   
Method:   -attachToToolForTargetRuntime:scaleFactor:assertOnFailureToAttach:assertOnPostLaunchRequestFailures:error:
Thread:   {name = (null), num = 1}
Please file a bug at http://bugreport.apple.com with this warning message and any useful information you can provide.
2014-06-05 11:15:06.914 ibtoold[952:507] [MT] DVTAssertions: ASSERTION FAILURE in /SourceCache/IDEInterfaceBuilderCocoaTouch/IDEInterfaceBuilderCocoaTouch-6153.11/InterfaceBuilder/Utilities/IBObjectMarshalling.m:45
Details:  Failed to launch Interface Builder Cocoa Touch Tool: Error Domain=com.apple.InterfaceBuilder Code=-1 "Encountered an error communicating with Interface Builder Cocoa Touch Tool." UserInfo=0x7fd09b3a1360 {NSUnderlyingError=0x7fd09861d710 "Failed to communicate with Interface Builder", NSLocalizedDescription=Encountered an error communicating with Interface Builder Cocoa Touch Tool., NSLocalizedRecoverySuggestion=Please check Console.app for crash reports for "Interface Builder Cocoa Touch Tool" for further information., NSLocalizedFailureReason=Interface Builder Cocoa Touch Tool (962) failed to launch and exited with status (null), signal 5.

xib是否可以在xcode beta上运行？