I have a small app written in SwiftUI and using SwiftData. It's been performing well for around a month but now suddenly I am getting the error below. No changes have been made to the models in use. Looking at the error it appears to be when SwiftData commits data but how can I tell what it is trying (and failing) to commit? Some way of knowing the model being referenced would help me diagnose this further. The error occurs at random intervals, though I'm guessing that's partly reflected by the design of SwiftData? [error] error: SQLCore dispatchRequest: exception handling request: <NSSQLSaveChangesRequestContext: 0x60000376af40> , -[__NSDictionaryM UTF8String]: unrecognized selector sent to instance 0x60000022adc0 with userInfo of (null) CoreData: error: SQLCore dispatchRequest: exception handling request: <NSSQLSaveChangesRequestContext: 0x60000376af40> , -[__NSDictionaryM UTF8String]: unrecognized selector sent to instance 0x60000022adc0 with userInfo of (null) *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSDictionaryM UTF8String]: unrecognized selector sent to instance 0x60000022adc0' *** First throw call stack: ( 0 CoreFoundation 0x00000001804ae138 __exceptionPreprocess + 172 1 libobjc.A.dylib 0x0000000180087db4 objc_exception_throw + 56 2 CoreFoundation 0x00000001804c2f88 +[NSObject(NSObject) instanceMethodSignatureForSelector:] + 0 3 CoreFoundation 0x00000001804b2288 forwarding + 1280 4 CoreFoundation 0x00000001804b45ac _CF_forwarding_prep_0 + 92 5 CoreData 0x0000000186537b90 -[NSSQLiteConnection execute] + 1104 6 CoreData 0x0000000186534b58 -[NSSQLiteConnection updateRow:forRequestContext:] + 1848 7 CoreData 0x0000000186634378 _executeSaveChangesRequest + 2216 8 CoreData 0x000 *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSDictionaryM UTF8String]: unrecognized selector sent to instance 0x60000022adc0' *** First throw call stack: ( 0 CoreFoundation 0x00000001804ae138 __exceptionPreprocess + 172 1 libobjc.A.dylib 0x0000000180087db4 objc_exception_throw + 56 2 CoreFoundation 0x00000001804c2f88 +[NSObject(NSObject) instanceMethodSignatureForSelector:] + 0 3 CoreFoundation 0x00000001804b2288 forwarding + 1280 4 CoreFoundation 0x00000001804b45ac _CF_forwarding_prep_0 + 92 5 CoreData 0x0000000186537b90 -[NSSQLiteConnection execute] + 1104 6 CoreData 0x0000000186534b58 -[NSSQLiteConnection updateRow:forRequestContext:] + 1848 7 CoreData 0x0000000186634378 _executeSaveChangesRequest + 2216 8 CoreData 0x000000018661e5e8 -[NSSQLSaveChangesRequestContext executeRequestCore:] + 28 9 CoreData 0x000000018641b28c -[NSSQLStoreRequestContext executeRequestUsingConnection:] + 248 10 CoreData 0x00000001864b4df4 __52-[NSSQLDefaultConnectionManager handleStoreRequest:]_block_invoke + 56 11 CoreData 0x000000018652d790 __37-[NSSQLiteConnection performAndWait:]_block_invoke + 40 12 libdispatch.dylib 0x00000001016e573c _dispatch_client_callout + 16 13 libdispatch.dylib 0x00000001016f648c _dispatch_lane_barrier_sync_invoke_and_complete + 144 14 CoreData 0x000000018652d248 -[NSSQLiteConnection performAndWait:] + 132 15 CoreData 0x00000001864b4d14 -[NSSQLDefaultConnectionManager handleStoreRequest:] + 204 16 CoreData 0x00000001865f29f4 -[NSSQLCoreDispatchManager routeStoreRequest:] + 220 17 CoreData 0x00000001864fa280 -[NSSQLCore dispatchRequest:withRetries:] + 168 18 CoreData 0x00000001864fc9e4 -[NSSQLCore executeRequest:withContext:error:] + 2116 19 CoreData 0x00000001864c6a84 __65-[NSPersistentStoreCoordinator executeRequest:withContext:error:]_block_invoke.383 + 9184 20 CoreData 0x00000001864bbac4 -[NSPersistentStoreCoordinator _routeHeavyweightBlock:] + 216 21 CoreData 0x00000001864c3ec8 -[NSPersistentStoreCoordinator executeRequest:withContext:error:] + 1100 22 CoreData 0x000000018647c8f8 -[NSManagedObjectContext save:] + 968 23 SwiftData 0x00000001cb408450 _swift_destroy_boxed_opaque_existential_0Tm + 50180 24 SwiftData 0x00000001cb4168d4 block_destroy_helper + 132 25 CoreData 0x00000001863cfec4 $sxs5Error_pIgrzo_xsAA_pIegrzo_lTR + 20 26 CoreData 0x00000001863d2198 $sxs5Error_pIgrzo_xsAA_pIegrzo_lTRTA + 20 27 CoreData 0x00000001863d1c8c $sSo22NSManagedObjectContextC8CoreDataE30_rethrowsHelper_performAndWait33_A0F63BA25A751D403694B89F4AD0A24ELL2fn7execute6rescuexyyyXEXE_xyKXExs5Error_pKXEtKlFyxyKcXEfU_yyXEfU + 108 28 CoreData 0x00000001863d04a4 $sIg_Ieg_TR + 20 29 CoreData 0x00000001863d04f4 $sIeg_IyB_TR + 20 30 CoreData 0x000000018648584c developerSubmittedBlockToNSManagedObjectContextPerform + 156 31 CoreData 0x0000000186485728 -[NSManagedObjectContext performBlockAndWait:] + 212 32 CoreData 0x00000001863d203c $sSo22NSManagedObjectContextC8CoreDataE14performAndWaityxxyKXEKlF + 352 33 SwiftData 0x00000001cb407b60 __swift_destroy_boxed_opaque_existential_0Tm + 47892 34 SwiftData 0x00000001cb4077a8 __swift_destroy_boxed_opaque_existential_0Tm + 46940 35 SwiftData 0x00000001cb40789c __swift_destroy_boxed_opaque_existential_0Tm + 47184 36 Foundation 0x0000000180e12924 __NSFireTimer + 56 37 CoreFoundation 0x000000018040f588 CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION + 28 Suggestions for narrowing down the cause gratefully accepted :-)