I have the same problem and my app is being rejected by Apple. I could not replicate the crash but I get crash report. the only clue is the warning message in the console: CoreData: warning: CoreData+CloudKit: -[NSCloudKitMirroringDelegate _performSetupRequest:]_block_invoke(1093): <NSCloudKitMirroringDelegate: 0x28045c7e0>: Successfully set up CloudKit integration for store (1F2E3F9B-9DD9-4D61-9DB9-ADD2A3DE9D8D): <NSSQLCore: 0x102117db0> (URL: file:///var/mobile/Containers/Data/Application/AAF688C5-D8C2-4A5E-A87D-B6F04537A941/Library/Application%20Support/shared.sqlite) CoreData: warning: CoreData+CloudKit: -[NSCloudKitMirroringDelegate _enqueueRequest:]_block_invoke_2(990): Failed to enqueue request: <NSCloudKitMirroringExportRequest: 0x281e65720> 82E677A0-8E75-470A-A5CC-59BBC6C53D38 CoreData: warning: CoreData+CloudKit: -[NSCloudKitMirroringDelegate finishedAutomatedRequestWithResult:](3372): Finished request '<NSCloudKitMirroringExportRequest: 0x281e65720> 82E677A0-8E75-470A-A5CC-59BBC6C53D38' with result: <NSCloudKitMirroringResult: 0x2833f6730> storeIdentifier: 0811C705-3EB2-4C73-BC5B-B96B43E4F2E0 success: 0 madeChanges: 0 error: Error Domain=NSCocoaErrorDomain Code=134417 "Request '<NSCloudKitMirroringExportRequest: 0x281e65720> 82E677A0-8E75-470A-A5CC-59BBC6C53D38' was cancelled because there is already a pending request of type 'NSCloudKitMirroringExportRequest'." UserInfo={NSLocalizedFailureReason=Request '<NSCloudKitMirroringExportRequest: 0x281e65720> 82E677A0-8E75-470A-A5CC-59BBC6C53D38' was cancelled because there is already a pending request of type 'NSCloudKitMirroringExportRequest'.} Exception Type: EXC_BREAKPOINT (SIGTRAP) Exception Codes: 0x0000000000000001, 0x00000001b5cab3e4 Termination Reason: SIGNAL 5 Trace/BPT trap: 5 Terminating Process: exc handler [32025] Triggered by Thread: 0 Thread 0 name: Dispatch queue: com.apple.main-thread Thread 0 Crashed: 0 libswiftCore.dylib 0x1b5cab3e4 _assertionFailure(_:_:file:line:flags:) + 264 1 BookShelf 0x1025dc790 closure #1 in CoreDataStack.persistentContainer.getter + 690064 (CoreDataStack.swift:0) 2 BookShelf 0x1025db82c CoreDataStack.persistentContainer.getter + 686124 (<compiler-generated>:0) 3 BookShelf 0x102584c60 closure #1 in SplashView.body.getter + 330848 (SplashView.swift:40) 4 BookShelf 0x1025848c8 SplashView.body.getter + 329928 (SplashView.swift:34) 5 SwiftUI 0x1bf7bb6ec 0x1bf75f000 + 378604 6 SwiftUI 0x1bf7a7830 0x1bf75f000 + 297008 7 SwiftUI 0x1bf79494c 0x1bf75f000 + 219468 8 SwiftUI 0x1bf7b2c80 0x1bf75f000 + 343168 9 SwiftUI 0x1bfd75310 0x1bf75f000 + 6382352 10 AttributeGraph 0x1dfe36e48 AG::Graph::UpdateStack::update() + 520 11 AttributeGraph 0x1dfe36748 AG::Graph::update_attribute(AG::data::ptr<AG::Node>, unsigned int) + 424 12 AttributeGraph 0x1dfe35490 AG::Subgraph::update(unsigned int) + 864 13 SwiftUI 0x1bf77d85c 0x1bf75f000 + 125020 14 SwiftUI 0x1c0b43928 0x1bf75f000 + 20859176 15 SwiftUI 0x1c018d8a8 0x1bf75f000 + 10676392 16 SwiftUI 0x1bf77aeac 0x1bf75f000 + 114348 17 SwiftUI 0x1bf774bb0 0x1bf75f000 + 89008 18 SwiftUI 0x1bf76f008 0x1bf75f000 + 65544 19 SwiftUI 0x1c0b438f0 0x1bf75f000 + 20859120 20 SwiftUI 0x1c0b437dc 0x1bf75f000 + 20858844 21 SwiftUI 0x1bf83bbd0 0x1bf75f000 + 904144 22 SwiftUI 0x1bf76c820 0x1bf75f000 + 55328 23 SwiftUI 0x1bf76c748 0x1bf75f000 + 55112 24 SwiftUI 0x1bf76c984 0x1bf75f000 + 55684 25 CoreFoundation 0x1bbf5b234 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 36 26 CoreFoundation 0x1bbee5410 __CFRunLoopDoObservers + 532 27 CoreFoundation 0x1bbf4519c __CFRunLoopRun + 1028 28 CoreFoundation 0x1bbf4a3ec CFRunLoopRunSpecific + 612 29 GraphicsServices 0x1f6b5835c GSEventRunModal + 164 30 UIKitCore 0x1be2d6f58 -[UIApplication _run] + 888 31 UIKitCore 0x1be2d6bbc UIApplicationMain + 340 32 SwiftUI 0x1bf91bc50 0x1bf75f000 + 1821776 33 SwiftUI 0x1bf8821ec 0x1bf75f000 + 1192428 34 SwiftUI 0x1bf86c294 0x1bf75f000 + 1102484 35 BookShelf 0x10253c0c8 main + 32968 (<compiler-generated>:0) 36 dyld 0x1db46cdec start + 2220