class AppDelegate: UIResponder, UIApplicationDelegate...の所にThread 1: signal SIGABRTの警告が出てしまいます

困っていること

CollectionViewでインスタグラムのような画面三分割を実装しようと思い、SimuSimulatorを起動させた際
以下のような警告が出てしまいました。

"Thread 1: signal SIGABRT"　が

Swift
1
2import UIKit
3
4@UIApplicationMain
5class AppDelegate: UIResponder, UIApplicationDelegate {
6
7    var window: UIWindow?
8
9
10    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
11        // Override point for customization after application launch.
12        return true
13    }
14
15    func applicationWillResignActive(_ application: UIApplication) {
16        // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
17        // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
18    }
19
20    func applicationDidEnterBackground(_ application: UIApplication) {
21        // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
22        // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
23    }
24
25    func applicationWillEnterForeground(_ application: UIApplication) {
26        // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
27    }
28
29    func applicationDidBecomeActive(_ application: UIApplication) {
30        // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
31    }
32
33    func applicationWillTerminate(_ application: UIApplication) {
34        // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
35    }
36
37
38}
39

の　class AppDelegate: UIResponder, UIApplicationDelegateの所に出てしまいます。

試してみたこと

ViewControllerのoutletの接続などを確認してみましたが、そこには警告は自分が確認した所見当たりませんでした。

Swiftファイルとエラー文

Swift
1import UIKit
2
3class FourthViewController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
4    
5    private var timelines: [Timeline] = Timelines.allTimelines() + Timelines.allTimelines()
6   
7    override func viewDidLoad() {
8        super.viewDidLoad()
9        
10        title = "Search"
11    }
12    
13    override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
14       return timelines.count
15        
16    }
17    
18    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
19        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Search", for: indexPath) as! SearchCollectionViewCell
20        let timeline = timelines[indexPath.row]
21        cell.timeline = timeline
22        return cell
23        
24    }
25    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: NSIndexPath) -> CGSize {
26        let screenWidth = UIScreen.main.bounds.width
27        let width = screenWidth/3
28        return CGSize(width: width, height: width)
29        
30    }
31    
32    
33    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
34        return 0.0
35    }
36    
37    
38    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
39        return 0.0
40    }
41   
42}
43

2019-06-20 12:08:40.818764+0900 nowscreen[24517:4596967] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '-[UICollectionViewController loadView] loaded the "XFM-ju-KV6-view-RS7-St-lex" nib but didn't get a UICollectionView.'
*** First throw call stack:
(
	0   CoreFoundation                      0x000000010bb736fb __exceptionPreprocess + 331
	1   libobjc.A.dylib                     0x000000010996fac5 objc_exception_throw + 48
	2   CoreFoundation                      0x000000010bb73555 +[NSException raise:format:] + 197
	3   UIKitCore                           0x0000000110c61399 -[UICollectionViewController loadView] + 802
	4   UIKitCore                           0x0000000110d23048 -[UIViewController loadViewIfRequired] + 172
	5   UIKitCore                           0x0000000110d23868 -[UIViewController view] + 27
	6   UIKitCore                           0x0000000110c59b70 -[UITabBarController transitionFromViewController:toViewController:transition:shouldSetSelected:] + 472
	7   UIKitCore                           0x0000000110c58ff9 -[UITabBarController transitionFromViewController:toViewController:] + 59
	8   UIKitCore                           0x0000000110c552c1 -[UITabBarController _setSelectedViewController:] + 410
	9   UIKitCore                           0x0000000110c55095 -[UITabBarController setSelectedViewController:] + 109
	10  UIKitCore                           0x0000000110c58f22 -[UITabBarController _tabBarItemClicked:] + 598
	11  UIKitCore                           0x0000000111327204 -[UIApplication sendAction:to:from:forEvent:] + 83
	12  UIKitCore                           0x0000000110b3841c -[UITabBar _sendAction:withEvent:] + 597
	13  UIKitCore                           0x0000000111327204 -[UIApplication sendAction:to:from:forEvent:] + 83
	14  UIKitCore                           0x0000000110d7cc19 -[UIControl sendAction:to:forEvent:] + 67
	15  UIKitCore                           0x0000000110d7cf36 -[UIControl _sendActionsForEvents:withEvent:] + 450
	16  UIKitCore                           0x0000000110b3ad94 -[UITabBar _buttonUp:] + 113
	17  UIKitCore                           0x0000000111327204 -[UIApplication sendAction:to:from:forEvent:] + 83
	18  UIKitCore                           0x0000000110d7cc19 -[UIControl sendAction:to:forEvent:] + 67
	19  UIKitCore                           0x0000000110d7cf36 -[UIControl _sendActionsForEvents:withEvent:] + 450
	20  UIKitCore                           0x0000000110d7beec -[UIControl touchesEnded:withEvent:] + 583
	21  UIKitCore                           0x000000011135feee -[UIWindow _sendTouchesForEvent:] + 2547
	22  UIKitCore                           0x00000001113615d2 -[UIWindow sendEvent:] + 4079
	23  UIKitCore                           0x000000011133fd16 -[UIApplication sendEvent:] + 356
	24  UIKitCore                           0x0000000111410293 __dispatchPreprocessedEventFromEventQueue + 3232
	25  UIKitCore                           0x0000000111412bb9 __handleEventQueueInternal + 5911
	26  CoreFoundation                      0x000000010badabe1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
	27  CoreFoundation                      0x000000010bada463 __CFRunLoopDoSources0 + 243
	28  CoreFoundation                      0x000000010bad4b1f __CFRunLoopRun + 1231
	29  CoreFoundation                      0x000000010bad4302 CFRunLoopRunSpecific + 626
	30  GraphicsServices                    0x00000001108872fe GSEventRunModal + 65
	31  UIKitCore                           0x0000000111325ba2 UIApplicationMain + 140
	32  nowscreen                           0x0000000109049f3b main + 75
	33  libdyld.dylib                       0x000000010cf7b541 start + 1
	34  ???                                 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)

教えていただきたいです。よろしくお願いいたします。