title: xcode iOS App Crashes after the renaming of view controller
body: <p><a href="https://i.stack.imgur.com/uuqyg.png" rel="nofollow noreferrer">Outlets</a> <a href="https://i.stack.imgur.com/8xHid.png" rel="nofollow noreferrer">Crash at Entry</a>  Crash Image Screenshot</p>
  
  <p><img src="https://i.stack.imgur.com/YudnR.png" alt="Crash Image Screenshot[1]"> </p>
  
  <p>I am getting an crash after I renamed my View Controller . Swift file to CalculatorViewController.swift
  I also tried refactoring new class name to be mirrored across all ports of entry to the app. I am getting Abort Signal Error. Please do help with this one! This is my error
  UPDATE: ERROR IN queue com.apple.mainthread (serial) Thread 1</p>
  
  <p>Crash point in code </p>
  
  <blockquote>
    <p>class AppDelegate: UIResponder, UIApplicationDelegate {</p>
  </blockquote>
  
  <p>UPDATE.</p>
  
  <blockquote>
    <p>2019-03-11 15:36:01.990755+0530 NDv2[4619:144763] Unknown class
    CalculatorViewController in Interface Builder file. 2019-03-11
    15:36:02.040903+0530 NDv2[4619:144763] <strong>* Terminating app due to
    uncaught exception 'NSUnknownKeyException', reason:
    '[ setValue:forUndefinedKey:]: this
    class is not key value coding-compliant for the key TextOutput.'
    *</strong> First throw call stack: (     0   CoreFoundation                      0x000000010ef3e1bb <strong>exceptionPreprocess + 331  1   libobjc.A.dylib<br>
    0x000000010cf58735 objc_exception_throw + 48  2   CoreFoundation<br>
    0x000000010ef3dd29 -[NSException raise] + 9   3   Foundation<br>
    0x000000010c983de4 -[NSObject(NSKeyValueCoding) setValue:forKey:] +
    292   4   UIKitCore                           0x00000001113a3292
    -[UIViewController setValue:forKey:] + 87     5   UIKitCore                           0x000000011163a573 -[UIRuntimeOutletConnection connect] + 109   6<br>
    CoreFoundation                      0x000000010ef29cfd -[NSArray
    makeObjectsPerformSelector:] + 317    7   UIKitCore<br>
    0x00000001116372b9 -[UINib instantiateWithOwner:options:] + 1814  8<br>
    UIKitCore                           0x00000001113aa452
    -[UIViewController _loadViewFromNibNamed:bundle:] + 383   9   UIKitCore                           0x00000001113aaddc -[UIViewController loadView] + 177   10  UIKitCore<br>
    0x00000001113ab0ee -[UIViewController loadViewIfRequired] + 175   11 
    UIKitCore                           0x00000001113ab940
    -[UIViewController view] + 27     12  UIKitCore                           0x0000000111a02c53 -[UIWindow addRootViewControllerViewIfPossible] +
    122   13  UIKitCore                           0x0000000111a0336e
    -[UIWindow _setHidden:forced:] + 294  14  UIKitCore                           0x0000000111a165c0 -[UIWindow makeKeyAndVisible] + 42   15  UIKitCore<br>
    0x00000001119c3833 -[UIApplication
    _callInitializationDelegatesForMainScene:transitionContext:] + 4595   16  UIKitCore                           0x00000001119c8c2f
    -[UIApplication _runWithMainScene:transitionContext:completion:] + 1623   17  UIKitCore                           0x00000001111e74e9
    __111-[__UICanvasLifecycleMonitor_Compatability _scheduleFirstCommitForScene:transition:firstActivation:completion:]_block_invoke
    + 866     18  UIKitCore                           0x00000001111f029c +[_UICanvas _enqueuePostSettingUpdateTransactionBlock:] + 153    19  UIKitCore                           0x00000001111e7126
    -[__UICanvasLifecycleMonitor_Compatability _scheduleFirstCommitForScene:transition:firstActivation:completion:] + 233     20  UIKitCore                           0x00000001111e7ae0
    -[__UICanvasLifecycleMonitor_Compatability activateEventsOnly:withContext:completion:] + 1085     21  UIKitCore<br>
    0x00000001111e5cb5 __82-[_UIApplicationCanvas
    _transitionLifecycleStateWithTransitionContext:completion:]_block_invoke
    + 795     22  UIKitCore                           0x00000001111e595f -[_UIApplicationCanvas _transitionLifecycleStateWithTransitionContext:completion:] + 435     23  UIKitCore                           0x00000001111eaa90
    __125-[_UICanvasLifecycleSettingsDiffAction performActionsForCanvas:withUpdatedScene:settingsDiff:fromSettings:transitionContext:]_block_invoke
    + 584     24  UIKitCore                           0x00000001111eb80e _performActionsWithDelayForTransitionContext + 100   25  UIKitCore                           0x00000001111ea7ef -[_UICanvasLifecycleSettingsDiffAction
    performActionsForCanvas:withUpdatedScene:settingsDiff:fromSettings:transitionContext:]
    + 221     26  UIKitCore                           0x00000001111ef93a -[_UICanvas scene:didUpdateWithDiff:transitionContext:completion:] + 392     27  UIKitCore                           0x00000001119c744e
    -[UIApplication workspace:didCreateScene:withTransitionContext:completion:] + 515     28 
    UIKitCore                           0x000000011156bd09
    -[UIApplicationSceneClientAgent scene:didInitializeWithEvent:completion:] + 357   29 
    FrontBoardServices                  0x000000011a0fc2da -[FBSSceneImpl
    _didCreateWithTransitionContext:completion:] + 448    30  FrontBoardServices                  0x000000011a107443
    __56-[FBSWorkspace client:handleCreateScene:withCompletion:]_block_invoke_2 + 271     31 
    FrontBoardServices                  0x000000011a106b3a
    __40-[FBSWorkspace _performDelegateCallOut:]_block_invoke + 53    32  libdispatch.dylib                   0x000000011047e602
    _dispatch_client_callout + 8  33  libdispatch.dylib                   0x0000000110481b78 _dispatch_block_invoke_direct + 301  34 
    FrontBoardServices                  0x000000011a13bba8
    __FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK</strong> + 30     35  FrontBoardServices                  0x000000011a13b860
    -[FBSSerialQueue _performNext] + 457  36  FrontBoardServices                  0x000000011a13be40 -[FBSSerialQueue _performNextFromRunLoopSource] +
    45    37  CoreFoundation                      0x000000010eea3721
    <strong>CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION</strong> + 17   38  CoreFoundation                      0x000000010eea2f93
    __CFRunLoopDoSources0 + 243   39  CoreFoundation                      0x000000010ee9d63f __CFRunLoopRun + 1263    40  CoreFoundation<br>
    0x000000010ee9ce11 CFRunLoopRunSpecific + 625     41  GraphicsServices<br>
    0x000000011713b1dd GSEventRunModal + 62   42  UIKitCore<br>
    0x00000001119ca81d UIApplicationMain + 140    43  NDv2<br>
    0x000000010c6291c7 main + 71  44  libdyld.dylib<br>
    0x00000001104f4575 start + 1 ) libc++abi.dylib: terminating with
    uncaught exception of type NSException</p>
  </blockquote>