NSRangeException Xcode

我的应用程序和CoreData出现问题。我正在使用CoreData保存用户信息，并且花了很长时间搜索如何正确使用核心数据。我已经找到并学会了使用方法，但是当我从IOS模拟器中删除该应用程序时，问题就开始了。当我这样做时，该应用程序冻结，并且控制台控制台中出现以下错误：

    2015-06-20 23:20:23.141 AppName[1767:218797] *** Terminating        
    app due to uncaught exception 'NSRangeException', reason: '*** -
    [__NSArrayI objectAtIndex:]: index 0 beyond bounds for empty array'
    *** First throw call stack:
    (
0   CoreFoundation                      0x000000010a70ec65 __exceptionPreprocess + 165
1   libobjc.A.dylib                     0x000000010c279bb7 objc_exception_throw + 45
2   CoreFoundation                      0x000000010a60517e -[__NSArrayI objectAtIndex:] + 190
3   YoutubeBillionaire                  0x000000010a103df2 _TFC18YoutubeBillionaire14ViewController11viewDidLoadfS0_FT_T_ + 2562
4   YoutubeBillionaire                  0x000000010a1059f2 _TToFC18YoutubeBillionaire14ViewController11viewDidLoadfS0_FT_T_ + 34
5   UIKit                               0x000000010b0de210 -[UIViewController loadViewIfRequired] + 738
6   UIKit                               0x000000010b0de40e -[UIViewController view] + 27
7   UIKit                               0x000000010aff92c9 -[UIWindow addRootViewControllerViewIfPossible] + 58
8   UIKit                               0x000000010aff968f -[UIWindow _setHidden:forced:] + 247
9   UIKit                               0x000000010b005e21 -[UIWindow makeKeyAndVisible] + 42
10  UIKit                               0x000000010afa9457 -[UIApplication _callInitializationDelegatesForMainScene:transitionContext:] + 2732
11  UIKit                               0x000000010afac1de -[UIApplication _runWithMainScene:transitionContext:completion:] + 1349
12  UIKit                               0x000000010afab0d5 -[UIApplication workspaceDidEndTransaction:] + 179
13  FrontBoardServices                  0x000000010dd895e5 __31-[FBSSerialQueue performAsync:]_block_invoke_2 + 21
14  CoreFoundation                      0x000000010a64241c __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 12
15  CoreFoundation                      0x000000010a638165 __CFRunLoopDoBlocks + 341
16  CoreFoundation                      0x000000010a637f25 __CFRunLoopRun + 2389
17  CoreFoundation                      0x000000010a637366 CFRunLoopRunSpecific + 470
18  UIKit                               0x000000010afaab42 -[UIApplication _run] + 413
19  UIKit                               0x000000010afad900 UIApplicationMain + 1282
20  YoutubeBillionaire                  0x000000010a1192e7 main + 135
21  libdyld.dylib                       0x000000010c9d1145 start + 1
   )
    libc++abi.dylib: terminating with uncaught exception of type NSException
    (lldb) 

感谢大家。