An app which was running successfully on iOS9-15 now crashes on launch on iOS9-12 when building with XCode13.1 (on M1 Pro). It crashes on unarchive of the main storyboard due to use of UITabBarAppearance which only exists on iOS13+ (see trace below). I have not edited my storyboard file since this was working on iOS 9-15 with previous XCode versions and the crash occurs before any of my code runs. In the hope it was a simulator-only issue (I have no old-iOS devices) I uploaded to the store but the app crashes on launch on real devices. https://apps.apple.com/nz/app/campermate-australia-nz/id1586561660 We could drop support for iOS9-11 but we still have plenty of iPhone 6 and 5 users (limited to iOS12). How can I fix this? 2021-12-15 10:51:09.954515+1300 TTG_Explore_Australia[36783:2248622] *** Terminating app due to uncaught exception 'NSInvalidUnarchiveOperationException', reason: 'Could not instantiate class named UITabBarAppearance because no class named UITabBarAppearance was found; the class needs to be defined in source code or linked in from a library (ensure the class is part of the correct target)' *** First throw call stack: ( 0  CoreFoundation           0x0000000113cae8db __exceptionPreprocess + 331 1  libobjc.A.dylib           0x0000000113259ac5 objc_exception_throw + 48 2  CoreFoundation           0x0000000113cae735 +[NSException raise:format:] + 197 3  UIFoundation            0x00000001176626c9 UINibDecoderDecodeObjectForValue + 360 4  UIFoundation            0x0000000117662af9 UINibDecoderDecodeObjectForValue + 1432 5  UIFoundation            0x0000000117662554 -[UINibDecoder decodeObjectForKey:] + 251 6  UIKitCore              0x000000011ca0c827 -[UINib instantiateWithOwner:options:] + 1306 7  UIKitCore              0x000000011cf28594 -[UIStoryboard instantiateViewControllerWithIdentifier:] + 181 8  UIKitCore              0x000000011cd8c809 -[UIApplication _loadMainStoryboardFileNamed:bundle:] + 111 9  UIKitCore              0x000000011cd8ccb1 -[UIApplication _loadMainInterfaceFile] + 274 10 UIKitCore              0x000000011cd8b3e5 -[UIApplication _runWithMainScene:transitionContext:completion:] + 1360 11 UIKitCore              0x000000011c5cfa4e __111-[__UICanvasLifecycleMonitor_Compatability _scheduleFirstCommitForScene:transition:firstActivation:completion:]_block_invoke + 904 12 UIKitCore              0x000000011c5d8346 +[_UICanvas _enqueuePostSettingUpdateTransactionBlock:] + 153 13 UIKitCore              0x000000011c5cf664 -[__UICanvasLifecycleMonitor_Compatability _scheduleFirstCommitForScene:transition:firstActivation:completion:] + 236 14 UIKitCore              0x000000011c5cffc0 -[__UICanvasLifecycleMonitor_Compatability activateEventsOnly:withContext:completion:] + 1091 15 UIKitCore              0x000000011c5ce332 __82-[_UIApplicationCanvas _transitionLifecycleStateWithTransitionContext:completion:]_block_invoke + 782 16 UIKitCore              0x000000011c5cdfe9 -[_UIApplicationCanvas _transitionLifecycleStateWithTransitionContext:completion:] + 433 17 UIKitCore              0x000000011c5d2d2e __125-[_UICanvasLifecycleSettingsDiffAction performActionsForCanvas:withUpdatedScene:settingsDiff:fromSettings:transitionContext:]_block_invoke + 576 18 UIKitCore              0x000000011c5d3988 _performActionsWithDelayForTransitionContext + 100 19 UIKitCore              0x000000011c5d2a95 -[_UICanvasLifecycleSettingsDiffAction performActionsForCanvas:withUpdatedScene:settingsDiff:fromSettings:transitionContext:] + 223 20 UIKitCore              0x000000011c5d7a48 -[_UICanvas scene:didUpdateWithDiff:transitionContext:completion:] + 392 21 UIKitCore              0x000000011cd89dc8 -[UIApplication workspace:didCreateScene:withTransitionContext:completion:] + 514 22 UIKitCore              0x000000011c94102f -[UIApplicationSceneClientAgent scene:didInitializeWithEvent:completion:] + 361 23 FrontBoardServices         0x000000011aeb4d25 -[FBSSceneImpl _didCreateWithTransitionContext:completion:] + 448 24 FrontBoardServices         0x000000011aebead6 __56-[FBSWorkspace client:handleCreateScene:withCompletion:]_block_invoke_2 + 283 25 FrontBoardServices         0x000000011aebe300 __40-[FBSWorkspace _performDelegateCallOut:]_block_invoke + 53 26 libdispatch.dylib          0x0000000114cc4db5 _dispatch_client_callout + 8 27 libdispatch.dylib          0x0000000114cc82ba _dispatch_block_invoke_direct + 300 28 FrontBoardServices         0x000000011aef00da __FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK__ + 30 29 FrontBoardServices         0x000000011aeefd92 -[FBSSerialQueue _performNext] + 451 30 FrontBoardServices         0x000000011aef0327 -[FBSSerialQueue _performNextFromRunLoopSource] + 42 31 CoreFoundation           0x0000000113c15db1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17 32 CoreFoundation           0x0000000113c15633 __CFRunLoopDoSources0 + 243 33 CoreFoundation           0x0000000113c0fcef __CFRunLoopRun + 1231 34 CoreFoundation           0x0000000113c0f4d2 CFRunLoopRunSpecific + 626 35 GraphicsServices          0x00000001169e62fe GSEventRunModal + 65 36 UIKitCore              0x000000011cd8cfc2 UIApplicationMain + 140 37 TTG_Explore_Australia        0x0000000100e63dd8 main + 104 38 ???                 0x0000000202b024fe 0x0 + 8635032830 39 ???                 0x0000000000000003 0x0 + 3 ) libc++abi.dylib: terminating with uncaught exception of type NSException *** Terminating app due to uncaught exception 'NSInvalidUnarchiveOperationException', reason: 'Could not instantiate class named UITabBarAppearance because no class named UITabBarAppearance was found; the class needs to be defined in source code or linked in from a library (ensure the class is part of the correct target)' terminating with uncaught exception of type NSException CoreSimulator 776.4 - Device: iPhone 8 Plus (B0A6FB7E-392D-40E7-AC7C-B6AF109ABE60) - Runtime: iOS 12.4 (16G73) - DeviceType: iPhone 8 Plus