当我尝试使用XCode 5使用推荐设置优化我现有的iOS应用程序到iOS7应用程序时 该应用程序正在崩溃，它显示以下日志
记录：
2013-09-20 19:21:56.794 -[UIStatusBarStyleRequest length]: unrecognized selector sent to instance 0xdb562d0
2013-09-20 19:21:57.660 *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIStatusBarStyleRequest length]: unrecognized selector sent to instance 0xdb562d0'
*** First throw call stack:
(
0 CoreFoundation 0x040e55e4 __exceptionPreprocess + 180
1 libobjc.A.dylib 0x037f48b6 objc_exception_throw + 44
2 CoreFoundation 0x04182903 -[NSObject(NSObject) doesNotRecognizeSelector:] + 275
3 CoreFoundation 0x040d590b ___forwarding___ + 1019
4 CoreFoundation 0x040d54ee _CF_forwarding_prep_0 + 14
5 Foundation 0x012318a2 -[NSDictionary(NSKeyValueCoding) valueForKey:] + 36
6 Application 0x000a9b65 -[NSDictionary(Subscript) objectForKeyedSubscript:] + 85
7 UIKit 0x01fe5fbc +[UIStatusBar _styleAttributesForRequest:] + 144
8 UIKit 0x01fe619e -[UIStatusBar _styleAttributesForRequest:] + 43
9 UIKit 0x01fe293a -[UIStatusBar requestStyle:animationParameters:] + 99
10 UIKit 0x01fe27bf -[UIStatusBar requestStyle:animated:] + 101
11 UIKit 0x01fe21be -[UIStatusBar forceUpdateStyleOverrides:] + 88
12 UIKit 0x01fe6510 -[UIStatusBar _evaluateServerRegistration] + 278
13 UIKit 0x01fe63f5 -[UIStatusBar didMoveToSuperview] + 33
14 UIKit 0x01be71a6 __45-[UIView(Hierarchy) _postMovedFromSuperview:]_block_invoke + 472
15 UIKit 0x01be6ef8 -[UIView(Hierarchy) _postMovedFromSuperview:] + 260
16 UIKit 0x01bf2031 -[UIView(Internal) _addSubview:positioned:relativeTo:] + 1847
17 UIKit 0x01be5521 -[UIView(Hierarchy) addSubview:] + 56
18 UIKit 0x01fd9ed8 -[UIStatusBarWindow setStatusBar:] + 339
19 UIKit 0x01b8be0e -[UIApplication _createStatusBarWithRequestedStyle:orientation:hidden:] + 203
20 UIKit 0x01b88e34 -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 436
21 UIKit 0x01b9d42c -[UIApplication handleEvent:withNewEvent:] + 3447
22 UIKit 0x01b9d999 -[UIApplication sendEvent:] + 85
23 UIKit 0x01b8ac35 _UIApplicationHandleEvent + 736
24 GraphicsServices 0x048782eb _PurpleEventCallback + 776
25 GraphicsServices 0x04877df6 PurpleEventCallback + 46
26 CoreFoundation 0x04060dd5 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 53
27 CoreFoundation 0x04060b0b __CFRunLoopDoSource1 + 523
28 CoreFoundation 0x0408b7ec __CFRunLoopRun + 2156
29 CoreFoundation 0x0408ab33 CFRunLoopRunSpecific + 467
30 CoreFoundation 0x0408a94b CFRunLoopRunInMode + 123
31 UIKit 0x01b886ed -[UIApplication _run] + 840
32 UIKit 0x01b8a94b UIApplicationMain + 1225
33 Application 0x0009333d main + 141
34 libdyld.dylib 0x03cd9725 start + 0
）
libc ++ abi.dylib：以NSException类型的未捕获异常终止
我还在谷歌上搜索了上述问题，但错误信息却没有找到任何关于此问题的内容。
请尽快帮我解决问题。
提前致谢