I see a chunk load error in the browser console. I already reported this: FB17664487

Hi there We're using CloudKit in our app which, generally, syncs data perfectly between devices. However, recently the sync has stopped working (some changes will never sync and the sync is delayed for several days even with the app open on all devices). CloudKit's logs show the error „You can't save and delete the same record" and „Already have a mirrored relationship registered for this key", etc. We’ve a hunch that this issue is related to a mirrored relationship of one database entity. Our scenario: We've subclassed the database entities. The database model (which we can't share publicly) contains mirrored relationships. We store very long texts in the database (similar to a Word document that contains markup data – in case that’s relevant). Deleting all data and starting with a completely new container and bundle identifier didn’t help (we tried that multiple times). This issue occurs on macOS (15.2（24C101) as well on iOS (18.2). Any hints on how to get the sync working again? Should we simply avoid mirrored relationships? Many thanks

Hi everyone, I’ve been working on migrating my app (SwimTimes, which helps swimmers track their times) to use Core Data + CKSyncEngine with Swift 6. After many iterations, forum searches, and experimentation, I’ve created a focused sample project that demonstrates the architecture I’m using. The good news: 👉 I believe the crashes I was experiencing are now solved, and the sync behavior is working correctly. 👉 The demo project compiles and runs cleanly with Swift 6. However, before adopting this as the final architecture, I’d like to ask the community (and hopefully Apple engineers) to validate a few critical points, especially regarding Swift 6 concurrency and Core Data contexts. Architecture Overview Persistence layer: Persistence.swift sets up the Core Data stack with a main viewContext and a background context for CKSyncEngine. Repositories: All Core Data access is abstracted into repository classes (UsersRepository, SwimTimesRepository), with async/await methods. SyncEngine: Wraps CKSyncEngine, handles system fields, sync tokens, and bridging between Core Data entities and CloudKit records. ViewModels: Marked @MainActor, exposing @Published arrays for SwiftUI. They never touch Core Data directly, only via repositories. UI: Simple SwiftUI views bound to the ViewModels. Entities: UserEntity → represents swimmers. SwimTimeEntity → times linked to a user (1-to-many). Current Status The project works and syncs across devices. But there are two open concerns I’d like validated: Concurrency & Memory Safety Am I correctly separating viewContext (main/UI) vs. background context (used by CKSyncEngine)? Could there still be hidden risks of race conditions or memory crashes that I’m not catching? Swift 6 Sendable Compliance Currently, I still need @unchecked Sendable in the SyncEngine and repository layers. What is the recommended way to fully remove these workarounds and make the code safe under Swift 6’s stricter concurrency rules? Request Please review this sample project and confirm whether the concurrency model is correct. Suggest how I can remove the @unchecked Sendable annotations safely. Any additional code improvements or best practices would also be very welcome — the intention is to share this as a community resource. I believe once finalized, this could serve as a good reference demo for Core Data + CKSyncEngine + Swift 6, helping others migrate safely. Environment iOS 18.5 Xcode 16.4 macOS 15.6 Swift 6 Sample Project Here is the full sample project on GitHub: 👉 [https://github.com/jarnaez728/coredata-cksyncengine-swift6] Thanks a lot for your time and for any insights! Best regards, Javier Arnáez de Pedro

I would like to have a SwiftData predicate that filters against an array of PersistentIdentifiers. A trivial use case could filtering Posts by one or more Categories. This sounds like something that must be trivial to do. When doing the following, however: let categoryIds: [PersistentIdentifier] = categoryFilter.map { $0.id } let pred = #Predicate<Post> { if let catId = $0.category?.persistentModelID { return categoryIds.contains(catId) } else { return false } } The code compiles, but produces the following runtime exception (XCode 26 beta, iOS 26 simulator): 'NSInvalidArgumentException', reason: 'unimplemented SQL generation for predicate : (TERNARY(item != nil, item, nil) IN {}) (bad LHS)' Strangely, the same code works if the array to filter against is an array of a primitive type, e.g. String or Int. What is going wrong here and what could be a possible workaround?

Hi, I keep trying to use transformable to store an array of strings with SwiftData, and I can see that it is activating the transformer, but it keeps saying that I am still using NSArray instead of NSData. *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Unacceptable type of value for attribute: property = "category"; desired type = NSData; given type = Swift.__SwiftDeferredNSArray; value = ( yo, gurt ).' terminating due to uncaught exception of type NSException CoreSimulator 1010.10 - Device: iPhone 16 18.0 (6879535B-3174-4025-AD37-ED06E60291AD) - Runtime: iOS 18.0 (22A3351) - DeviceType: iPhone 16 Message from debugger: killed @Model class MyModel: Identifiable, Equatable { @Attribute(.transformable(by: StringArrayTransformer.self)) var category: [String]? @Attribute(.transformable(by: StringArrayTransformer.self)) var amenities: [String]? var image: String? var parentChunck: HenricoPostDataChunk_V1? init(category: [String]?, amenities: [String]?) { self.category = category self.amenities = amenities } } class StringArrayTransformer: ValueTransformer { override func transformedValue(_ value: Any?) -> Any? { print(value) guard let array = value as? [String] else { return nil } let data = try? JSONSerialization.data(withJSONObject: array, options: []) print(data) return data } override func reverseTransformedValue(_ value: Any?) -> Any? { guard let data = value as? Data else { return nil } let string = (try? JSONSerialization.jsonObject(with: data, options: [])) as? [String] print(string) return string } override class func transformedValueClass() -> AnyClass { return NSData.self } override class func allowsReverseTransformation() -> Bool { return true } static func register() { print("regitsering") ValueTransformer.setValueTransformer(StringArrayTransformer(), forName: .stringArrayTransformerName) } } extension NSValueTransformerName { static let stringArrayTransformerName = NSValueTransformerName("StringArrayTransformer") }

When my app starts it loads data (of vehicle models, manufacturers, ...) from JSON files into CoreData.  This content is static. Some CoreData entities have fields that can be set by the user, for example an isFavorite boolean field. How do I tell CloudKit that my CoreData objects are 'static' and must not be duplicated on other devices (that will also load it from JSON files). In other words, how can I make sure that the CloudKit knows that the record created from JSON for vehicle model XYZ on one device is the same record that was created from JSON on any other device? I'm using NSPersistentCloudKitContainer.

Hi, I have developed a calendar app with swiftData. I have set it to sync iCloud. When testing it, it seems that everything is fine. But after it's released, today, I uninstalled it and reinstalled it again. And I found that iCloud hasn't sync with local swiftData for six days. I have lost six days agenda and relevant information. I have checked the document, and it's said that there is no method to force to sync with iCloud. How to solve the issue? I think that the users can't forgive that it hasn't synced for six days. Best Wishes,

Hello, My app has had CloudKit enabled for a while, but it's not working. I get the error "Invalid bundle ID for container". Configure CloudKit in your project from TN3164 suggests changing to a new container. I tried changing to a new container, but this leads to data loss. The article recommends: "If your CloudKit container is already used in the production environment and switching to a new container leads to data loss, consider filing a feedback report with the following information to request manually associating your CloudKit container with your app ID." Where can I request this manual association? Is there anything else I can do? Thank you for your time and assistance. I’d appreciate a prompt resolution, as this issue is blocking our update. Looking forward to guidance.

We are using AgeRangeService.requestAgeRange(ageGates:in:) with an age gate of 18 to verify adult users. The system prompt always displays the lower-bound wording (“17 or Younger”), even when the app’s requirement is to verify users who are 18 or older. We understand the UI is system-controlled; however, this wording causes confusion for users, QA, and product teams, as it appears to indicate a child-only flow even when requesting adult verification. Based on the demonstration video, it appears that they have another more coherent message. In Apple's example, it is different, and it is correct that we need to specify 18 years or older in the implementation. A little more context might be helpful, but we are creating a kind of wrapper with React Native that receives that value as a parameter, which is 18.

I'm experiencing the following error with my SwiftData container when running a build: Code=134504 "Cannot use staged migration with an unknown model version." Code Structure - Summary I am using a versionedSchema to store multiple models in SwiftData. I started experiencing this issue when adding two new models in the newest Schema version. Starting from the current public version, V4.4.6, there are two migrations. Migration Summary The first migration is to V4.4.7. This is a lightweight migration removing one attribute from one of the models. This was tested and worked successfully. The second migration is to V5.0.0. This is a custom migration adding two new models, and instantiating instances of the two new models based on data from instances of the existing models. In the initial testing of this version, no issues were observed. Issue and Steps to Reproduce Reproduction of issue: Starting from a fresh build of the publicly released V4.4.6, I run a new build that contains both Schema Versions (V4.4.7 and V5.0.0), and their associated migration stages. This builds successfully, and the container successfully migrates to V5.0.0. Checking the default.store file, all values appear to migrate and instantiate correctly. The second step in reproduction of the issue is to simply stop running the build, and then rebuild, without any code changes. This fails to initialize the model container every time afterwards. Going back to the simulator after successive builds are stopped in Xcode, the app launches and accesses/modifies the model container as normal. Supplementary Issue: I have been putting up with the same, persistent issue in the Xcode Preview Canvas of "Failed to Initialize Model Container" This is a 5 in 6 build issue, where builds will work at random. In the case of previews, I have cleared all data associated with all previews multiple times. The only difference being that the simulator is a 100% failure rate after the initial, successful initialization. I assume this is due to the different build structure of previews. Lastly, of note, the Xcode previews fail at the same line in instantiating the model container as the simulator does. From my research into this issue, people say that the Xcode preview is instantiating from elsewhere. I do have a separate model container set up specifically for canvas previews, but the error does not occur in that container, but rather the app's main container. Possible Contributing Factors & Tested Facts iOS: While I have experienced issues with SwiftData and the complier in iOS 26, I can rule that out as the issue here. This has been tested on simulators running iOS 18.6, 26.0.1, and 26.1, all encountering failures to initialize model container. While in iOS 18, subsequent builds after the successful migration did work, I did eventually encounter the same error and crash. In iOS 26.0.1 and 26.1, these errors come immediately on the second build. Container Initialization for V4.4.6 do { container = try ModelContainer( for: Job.self, JobTask.self, Day.self, Charge.self, Material.self, Person.self, TaskCategory.self, Service.self, migrationPlan: JobifyMigrationPlan.self ) } catch { fatalError("Failed to Initialize Model Container") } Versioned Schema Instance for V4.4.6 (V4.4.7 differs only by versionIdentifier) static var versionIdentifier = Schema.Version(4, 4, 6) static var models: [any PersistentModel.Type] { [Job.self, JobTask.self, Day.self, Charge.self, Material.self, Person.self, TaskCategory.self, Service.self] } Container Initialization for V5.0.0 do { let schema = Schema([Jobify.self, JobTask.self, Day.self, Charge.self, MaterialItem.self, Person.self, TaskCategory.self, Service.self, ServiceJob.self, RecurerRule.self]) container = try ModelContainer( for: schema, migrationPlan: JobifyMigrationPlan.self ) } catch { fatalError("Failed to Initialize Model Container") } Versioned Schema Instance for V5.0.0 static var versionIdentifier = Schema.Version(5, 0, 0) static var models: [any PersistentModel.Type] { [ JobifySchemaV500.Job.self, JobifySchemaV500.JobTask.self, JobifySchemaV500.Day.self, JobifySchemaV500.Charge.self, JobifySchemaV500.Material.self, JobifySchemaV500.Person.self, JobifySchemaV500.TaskCategory.self, JobifySchemaV500.Service.self, JobifySchemaV500.ServiceJob.self, JobifySchemaV500.RecurerRule.self ] } Addressing Differences in Object Names Type-aliasing: All my model types are type-aliased for simplification in view components. All types are aliased as 'JobifySchemeV446.<#Name#>' in V.4.4.6, and 'JobifySchemaV500.<#Name#>' in V5.0.0 Issues with iOS 26: My type-aliases dating back to iOS 17 overlapped with lower level objects in Swift, including 'Job' and 'Material'. These started to be an issue with initializing the model container when running in iOS 26. The type aliases have been renamed since, however the V4.4.6 build with the old names runs and builds perfectly fine in iOS 26 If there is any other code that may be relevant in determining where this error is occurring, I would be happy to add it. My current best theory is simply that I have mistakenly omitted code relevant to the SwiftData Migration.

Hi! I use Tips with CloudKit and it works very well, however when a user want to remove their data from CloudKit, how to do that? In CoreData with CloudKit area, NSPersistentCloudKitContainer have purgeObjectsAndRecordsInZone to delete both local managed objects and CloudKit records, however there is no information about the TipKit deletion. Does anyone know ideas?

I have encountered an issue with a customer’s data access after they migrated to a different iCloud account, and I’m looking for guidance. The Situation: The customer was logged into their account on my app, which was associated with a specific iCloud account (iCloud A). They had all their app data available while using iCloud A. The customer then switched to a new iCloud account (iCloud B) on the same device, while still using the same app account. After switching iCloud accounts, their data is no longer visible in the app or my CloudKit dashboard. My Investigation: I accessed the customer’s CloudKit data via the CloudKit Console, acting as their iCloud account. I couldn’t find the private database zone or any of their records when accessing iCloud A through the console. I don’t believe the data was deleted since actions performed under iCloud B shouldn’t affect data stored in iCloud A. My Hypothesis: I suspect that the customer’s old iCloud account (iCloud A) may have downgraded or stopped paying for iCloud storage. If the iCloud subscription is inactive or expired, could that prevent me from accessing their CloudKit data? Would renewing the iCloud subscription for iCloud A restore access to the missing data? Questions: Does an unpaid or expired iCloud account restrict access to CloudKit records, even if they weren’t deleted? Would paying for iCloud storage again restore the data previously stored in CloudKit? Is there any way to recover the customer’s CloudKit data if they are unable to access their old iCloud account? If anyone has a simpler approach to recovering the customer’s iCloud-stored app data or has experience dealing with iCloud migrations like this, I’d appreciate your insights. Thank you in advance for any advice!

Hello 👋, I encounter the "This model instance was invalidated because its backing data could no longer be found the store" crash with SwiftData. Which from what I understood means I try to access a model after it has been removed from the store (makes sense). I made a quick sample to reproduce/better understand because there some case(s) I can't figure it out. Let's take a concrete example, we have Home model and a Home can have many Room(s). // Sample code @MainActor let foo = Foo() // A single reference let database = Database(modelContainer: sharedModelContainer) // A single reference @MainActor class Foo { // Properties to explicilty keep reference of model(s) for the purpose of the POC var _homes = [Home]() var _rooms = [Room]() func fetch() async { let homes = await database.fetch().map { sharedModelContainer.mainContext.model(for: $0) as! Home } print(ObjectIdentifier(homes[0]), homes[0].rooms?.map(\.id)) // This will crash here or not. } // Same version of a delete function with subtle changes. // Depending on the one you use calling delete then fetch will result in a crash or not. // Keep a reference to only homes == NO CRASH func deleteV1() async { self._homes = await database.fetch().map { sharedModelContainer.mainContext.model(for: $0) as! Home } await database.delete() } // Keep a reference to only rooms == NO CRASH func deleteV2() async { self._rooms = await database.fetch().map { sharedModelContainer.mainContext.model(for: $0) as! Home }[0].rooms ?? [] await database.delete() } // Keep a reference to homes & rooms == CRASH 💥 func deleteV3() async { self._homes = await database.fetch().map { sharedModelContainer.mainContext.model(for: $0) as! Home } self._rooms = _homes[0].rooms ?? [] // or even only retain reference to rooms that have NOT been deleted 🤔 like here "id: 2" make it crash // self._rooms = _homes[0].rooms?.filter { r in r.id == "2" } ?? [] await database.delete() } } Calling deleteV() then fetch() will result in a crash or not depending on the scenario. I guess I understand deleteV1, deleteV2. In those case an unsaved model is served by the model(for:) API and accessing properties later on will resolve correctly. The doc says: "The identified persistent model, if known to the context; otherwise, an unsaved model with its persistentModelID property set to persistentModelID." But I'm not sure about deleteV3. It seems the ModelContext is kind of "aware" there is still cyclic reference between my models that are retained in my code so it will serve these instances instead when calling model(for:) API ? I see my home still have 4 rooms (instead of 2). So I then try to access rooms that are deleted and it crash. Why of that ? I mean why not returning home with two room like in deleteV1 ? Because SwiftData heavily rely on CoreData may be I miss a very simple thing here. If someone read this and have a clue for me I would be extremely graceful. PS: If someone wants to run it on his machine here's some helpful code: // Database let sharedModelContainer: ModelContainer = { let schema = Schema([ Home.self, Room.self, ]) let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false) debugPrint(modelConfiguration.url.absoluteString.replacing("%20", with: "\\ ")) return try! ModelContainer(for: schema, configurations: [modelConfiguration]) }() extension Database { static let shared = Database(modelContainer: sharedModelContainer) } @ModelActor actor Database { func insert() async { let r1 = Room(id: "1", name: "R1") let r2 = Room(id: "2", name: "R2") let r3 = Room(id: "3", name: "R3") let r4 = Room(id: "4", name: "R4") let home = Home(id: "1", name: "My Home") home.rooms = [r1, r2, r3, r4] modelContext.insert(home) try! modelContext.save() } func fetch() async -> [PersistentIdentifier] { try! modelContext.fetchIdentifiers(FetchDescriptor<Home>()) } @MainActor func delete() async { let mainContext = sharedModelContainer.mainContext try! mainContext.delete( model: Room.self, where: #Predicate { r in r.id == "1" || r.id == "4" } ) try! mainContext.save() // 🤔 Calling fetch here seems to solve crash too, force home relationship to be rebuild correctly ? // let _ = try! sharedModelContainer.mainContext.fetch(FetchDescriptor<Home>()) } } // Models @Model class Home: Identifiable { @Attribute(.unique) public var id: String var name: String @Relationship(deleteRule: .cascade, inverse: \Room.home) var rooms: [Room]? init(id: String, name: String, rooms: [Room]? = nil) { self.id = id self.name = name self.rooms = rooms } } @Model class Room: Identifiable { @Attribute(.unique) public var id: String var name: String var home: Home? init(id: String, name: String, home: Home? = nil) { self.id = id self.name = name self.home = home } }

I get the following fatal error when the user clicks Save in AddProductionView. Fatal error: Duplicate keys of type 'AnyHashable' were found in a Dictionary. This usually means either that the type violates Hashable's requirements, or that members of such a dictionary were mutated after insertion. As far as I’m aware, SwiftData automatically makes its models conform to Hashable, so this shouldn’t be a problem. I think it has something to do with the picker, but for the life of me I can’t see what. This error occurs about 75% of the time when Save is clicked. I'm using Xcode 16.2 and iPhone SE 2nd Gen. Any help would be greatly appreciated… Here is my code: import SwiftUI import SwiftData @main struct MyApp: App { var body: some Scene { WindowGroup { ContentView() .modelContainer(for: Character.self, isAutosaveEnabled: false) } } } @Model final class Character { var name: String var production: Production var myCharacter: Bool init(name: String, production: Production, myCharacter: Bool = false) { self.name = name self.production = production self.myCharacter = myCharacter } } @Model final class Production { var name: String init(name: String) { self.name = name } } struct ContentView: View { @State private var showingSheet = false var body: some View { Button("Add", systemImage: "plus") { showingSheet.toggle() } .sheet(isPresented: $showingSheet) { AddProductionView() } } } struct AddProductionView: View { @Environment(\.dismiss) private var dismiss @Environment(\.modelContext) var modelContext @State var production = Production(name: "") @Query var characters: [Character] @State private var characterName: String = "" @State private var selectedCharacter: Character? var filteredCharacters: [Character] { characters.filter { $0.production == production } } var body: some View { NavigationStack { Form { Section("Details") { TextField("Title", text: $production.name) } Section("Characters") { List(filteredCharacters) { character in Text(character.name) } HStack { TextField("Character", text: $characterName) Button("Add") { let newCharacter = Character(name: characterName, production: production) modelContext.insert(newCharacter) characterName = "" } .disabled(characterName.isEmpty) } if !filteredCharacters.isEmpty { Picker("Select your role", selection: $selectedCharacter) { Text("Select") .tag(nil as Character?) ForEach(filteredCharacters) { character in Text(character.name) .tag(character as Character?) } } .pickerStyle(.menu) } } } .toolbar { Button("Save") { //Fatal error: Duplicate keys of type 'AnyHashable' were found in a Dictionary. This usually means either that the type violates Hashable's requirements, or that members of such a dictionary were mutated after insertion. if let selectedCharacter = selectedCharacter { selectedCharacter.myCharacter = true } modelContext.insert(production) do { try modelContext.save() } catch { print("Failed to save context: \(error)") } dismiss() } .disabled(production.name.isEmpty || selectedCharacter == nil) } } } }

I have a SwiftData application that is using CloudKit. If user is on new device. How can I check and fetch data, instead of just waiting for it happen on its own randomly? For example, I have onboarding which I do not want user to go through again if they already have an active installation. Seems like SwiftData is severely limited in pretty much every way, specially any useful CloudKit debugging or control functionality.

if it set com.apple.CoreData.ConcurrencyDebug 1 as launch arg the app always crashes and i cant proceed into the app. is there a way to only raise a warning for these issues so that i can go into the app and check every place in one session for coredata errors?

I am working on a software where we want to add the feature to share the whole database with the other user. Database is iCloud combined with coredata. The other user(s) should be able to edit /delete and even create new objects in the share. I did this with this code witch directly from sample code let participants = try await ckConainer.fetchParticipants(matching: [lookupInfo], into: selectedStore) for participant in participants { participant.permission = .readWrite participant.role = .privateUser share.addParticipant(participant) } try await ckConainer.persistUpdatedShare(share, in: selectedStore) the other user gets invited and I can see this in iCloud database that the other user is invited with status invited. but the other user never gets a mail or something to accept and join the share. How does the other needs to accept the invitation ?

Using SwiftData and this is the simplest example I could boil down: @Model final class Item { var timestamp: Date var tag: Tag? init(timestamp: Date) { self.timestamp = timestamp } } @Model final class Tag { var timestamp: Date init(timestamp: Date) { self.timestamp = timestamp } } Notice Tag has no reference to Item. So if I create a bunch of items and set their Tag. Later on I add the ability to delete a Tag. Since I haven't added inverse relationship Item now references a tag that no longer exists so so I get these types of errors: SwiftData/BackingData.swift:875: Fatal error: This model instance was invalidated because its backing data could no longer be found the store. PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(url: x-coredata://EEC1D410-F87E-4F1F-B82D-8F2153A0B23C/Tag/p1), implementation: SwiftData.PersistentIdentifierImplementation) I think I understand now that I just need to add the item reference to Tag and SwiftData will nullify all Item references to that tag when a Tag is deleted. But, the damage is already done. How can I iterate through all Items that referenced a deleted tag and set them to nil or to a placeholder Tag? Or how can I catch that error and fix it when it comes up? The crash doesn't occur when loading an Item, only when accessing item.tag?.timestamp, in fact, item.tag?.id is still ok and doesn't crash since it doesn't have to load the backing data. I've tried things like just looping through all items and setting tag to nil, but saving the model context fails because somewhere in there it still tries to validate the old value. Thanks!

It takes a few seconds, sometimes a few minutes for records to be downloaded back from CloudKit when the user reinstalls the app, which leads users to thinking their data was lost. I would like to know if there’s any way to provide a visual feedback about the current CloudKit sync status so I can let users know their data is being in fact downloaded back to their devices.

I've run into a strange issue. If a sheet loads a view that has a SwiftData @Query, and there is an if statement in the view body, I get the following error when running an iOS targetted SwiftUI app under MacOS 26.1: Set a .modelContext in view's environment to use Query While the view actually ends up loading the correct data, before it does, it ends up re-creating the sqlite store (opening as /dev/null). The strange thing is that this only happens if there is an if statement in the body. The statement need not ever evaluate true, but it causes the issue. Here's an example. It's based on the default xcode new iOS project w/ SwiftData: struct ContentView: View { @State private var isShowingSheet = false var body: some View { Button(action: { isShowingSheet.toggle() }) { Text("Show Sheet") } .sheet(isPresented: $isShowingSheet, onDismiss: didDismiss) { VStack { ContentSheetView() } } } func didDismiss() { } } struct ContentSheetView: View { @Environment(\.modelContext) private var modelContext @Query public var items: [Item] @State var fault: Bool = false var body: some View { VStack { if fault { Text("Fault!") } Button(action: addItem) { Label("Add Item", systemImage: "plus") } List { ForEach(items) { item in Text(item.timestamp, format: Date.FormatStyle(date: .numeric, time: .standard)) } } } } private func addItem() { withAnimation { let newItem = Item(timestamp: Date()) modelContext.insert(newItem) } } } It requires some data to be added to trigger, but after adding it and dismissing the sheet, opening up the sheet with trigger the Set a .modelContext in view's environment to use Query. Flipping on -com.apple.CoreData.SQLDebug 1 will show it trying to recreate the database. If you remove the if fault { Text("Fault!") } line, it goes away. It also doesn't appear to happen on iPhones or in the iPhone simulator. Explicitly passing modelContext to the ContentSheetView like ContentSheetView().modelContext(modelContext) also seems to fix it. Is this behavior expected?