Bardzo często, gdy próbuję edytować UILabels w serii ujęć, Xcode ulega awarii. Jakieś pomysły, które mogą to powodować? Wygląda na to, że ma coś wspólnego z jednym z ograniczeń autolayout. Oto raport o błędzie:

Process:         Xcode [43938]
Path:            /Applications/Xcode.app/Contents/MacOS/Xcode
Identifier:      com.apple.dt.Xcode
Version:         4.5 (1839)
Build Info:      IDEApplication-1839000000000000~3
App Item ID:     497799835
App External ID: 10747437
Code Type:       X86-64 (Native)
Parent Process:  launchd [43283]

Date/Time:       2012-10-01 09:43:36.443 -0400
OS Version:      Mac OS X 10.7.4 (11E53)
Report Version:  9
Sleep/Wake UUID: 8C7C93A7-0BEF-42C6-944C-488D8C7896DD

Interval Since Last Report:          152594 sec
Crashes Since Last Report:           6
Per-App Interval Since Last Report:  135715 sec
Per-App Crashes Since Last Report:   5
Anonymous UUID:                      E745D8FE-362B-4FD2-8594-7EC5C26767B2

Crashed Thread:  0  Dispatch queue: com.apple.main-thread

Exception Type:  EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000

Application Specific Information:
ProductBuildVersion: 4G182
ASSERTION FAILURE in /SourceCache/IDEInterfaceBuilderCocoaTouch/IDEInterfaceBuilderCocoaTouch-1926/IBPlugin/Utilities/IBObjectMarshalling.m:651
Details:  Failed to start deciding frames for IBNSLayoutConstraint, IBUILabel, IBUITabBarItem, IBUITableView, IBUIView, and IBUIViewController.

Interface Builder encountered an error communicating with the iOS Simulator. If you choose to file a crash report or radar for this issue, please check Console.app for crash reports for "Interface Builder Cocoa Touch Tool" and include their content in your crash report.

Exception name: IBAssertionFailure
Exception reason: ASSERTION FAILURE: realConstraint
Reason:     Should have found real constraint for represented constraint <NSLayoutConstraint:0x86a8c30 H:[UIView:0x868a0f0(71)]>
File:       /SourceCache/IBAutolayoutFoundationIOS/IBAutolayoutFoundation-1818/Framework/Classes/Arbitration/IBAutolayoutEngine.m:223
Method:     __76-[IBAutolayoutEngine realConstraintsFromCollectionOfRepresentedConstraints:]_block_invoke_0
Exception backtrace: 
  0. CoreFoundation           0x022a4012 __exceptionPreprocess
  1. libobjc.A.dylib          0x01703e7e objc_exception_throw
  2. CoreFoundation           0x0232cfb1 -[NSException raise]
  3. ???                      0x0000beae [IBCocoaTouchTool startAutolayoutFrameDecisionSessionWithRequest:document:]
  4. ???                      0x000342a5 [IBMessageReceiveChannel deliverMessage:toTarget:withArguments:result:]
  5. ???                      0x00033fa9 [IBMessageReceiveChannel deliverMessage:toTarget:withArguments:result:]
  6. ???                      0x00033c47 [IBMessageReceiveChannel runBlockingReceiveLoopNotifyingQueue:notifyingTarget:]
  7. libdispatch.dylib        0x04c3d731 _dispatch_barrier_sync_f_slow_invoke
  8. libdispatch.dylib        0x04c4c014 _dispatch_client_callout
  9. libdispatch.dylib        0x04c3c7d5 _dispatch_main_queue_callback_4CF
 10. CoreFoundation           0x0224aaf5 __CFRunLoopRun
 11. CoreFoundation           0x02249f44 CFRunLoopRunSpecific
 12. CoreFoundation           0x02249e1b CFRunLoopRunInMode
 13. Foundation               0x01308c7c -[NSRunLoop(NSRunLoop) runMode:beforeDate:]
 14. ???                      0x0000cf06 [IBCocoaTouchTool startServingReceiveChannel:]
 15. ???                      0x0000d09f [IBCocoaTouchTool startServingWithSocket:]
 16. ???                      0x0000e1b7 [IBCocoaTouchTool .cxx_destruct]
 17. ???                      0x00002365 ???
Exception info:{
}