I don't know how to solve this problem. I haven't got breakpoints and I have revised all my outlets of the main.storyboard and I can't find the error. 2020-01-05 20:42:51.299090+0100 Contacts[1999:158537] *** Assertion failure in +[UIStoryboard storyboardWithName:bundle:], /BuildRoot/Library/Caches/com.apple.xbs/Sources/UIKitCore_Sim/UIKit-3901.4.2/UIStoryboard.m:1002020-01-05 20:42:51.330348+0100 Contacts[1999:158537] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid parameter not satisfying: [name length] > 0'*** First throw call stack:( 0 CoreFoundation 0x00007fff23c7127e __exceptionPreprocess + 350 1 libobjc.A.dylib 0x00007fff513fbb20 objc_exception_throw + 48 2 CoreFoundation 0x00007fff23c70ff8 +[NSException raise:format:arguments:] + 88 3 Foundation 0x00007fff256e9b51 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 191 4 UIKitCore 0x00007fff481f85d3 +[UIStoryboard storyboardWithName:bundle:] + 576 5 UIKitCore 0x00007fff476da5be -[UISceneConfiguration initWithName:sessionRole:] + 2026 6 UIKitCore 0x00007fff476d9da8 +[UISceneConfiguration configurationWithName:sessionRole:] + 87 7 UIKitCore 0x00007fff476dba1f -[UISceneSession _initWithIdentifier:sessionRole:configurationName:] + 178 8 UIKitCore 0x00007fff4808eebd -[UIApplication _connectUISceneFromFBSScene:transitionContext:] + 327 9 UIKitCore 0x00007fff4808f4b2 -[UIApplication workspace:didCreateScene:withTransitionContext:completion:] + 304 10 UIKitCore 0x00007fff47bfa7f5 -[UIApplicationSceneClientAgent scene:didInitializeWithEvent:completion:] + 361 11 FrontBoardServices 0x00007fff365d6165 -[FBSSceneImpl _callOutQueue_agent_didCreateWithTransitionContext:completion:] + 442 12 FrontBoardServices 0x00007fff365fc4d8 __86-[FBSWorkspaceScenesClient sceneID:createWithParameters:transitionContext:completion:]_block_invoke.154 + 102 13 FrontBoardServices 0x00007fff365e0c45 -[FBSWorkspace _calloutQueue_executeCalloutFromSource:withBlock:] + 220 14 FrontBoardServices 0x00007fff365fc169 __86-[FBSWorkspaceScenesClient sceneID:createWithParameters:transitionContext:completion:]_block_invoke + 355 15 libdispatch.dylib 0x0000000108f0ad48 _dispatch_client_callout + 8 16 libdispatch.dylib 0x0000000108f0dcb9 _dispatch_block_invoke_direct + 300 17 FrontBoardServices 0x00007fff3662237e __FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK__ + 30 18 FrontBoardServices 0x00007fff3662206c -[FBSSerialQueue _queue_performNextIfPossible] + 441 19 FrontBoardServices 0x00007fff3662257b -[FBSSerialQueue _performNextFromRunLoopSource] + 22 20 CoreFoundation 0x00007fff23bd4471 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17 21 CoreFoundation 0x00007fff23bd439c __CFRunLoopDoSource0 + 76 22 CoreFoundation 0x00007fff23bd3bcc __CFRunLoopDoSources0 + 268 23 CoreFoundation 0x00007fff23bce87f __CFRunLoopRun + 1263 24 CoreFoundation 0x00007fff23bce066 CFRunLoopRunSpecific + 438 25 GraphicsServices 0x00007fff384c0bb0 GSEventRunModal + 65 26 UIKitCore 0x00007fff48092d4d UIApplicationMain + 1621 27 Contacts 0x0000000108be25d4 main + 116 28 libdyld.dylib 0x00007fff5227ec25 start + 1)libc++abi.dylib: terminating with uncaught exception of type NSException(lldb)