Overview I'm developing a document-based app for macOS using SwiftData. When I undo/redo changes using Command-Z/Command-Shift-Z, the app reliably crashes with the following error: SwiftData/ModelSnapshot.swift:46: Fatal error: Unexpected backing data for snapshot creation: SwiftData._FullFutureBackingData<DocumentTest.ChildItem> And before the app crashes, what always happens is that UndoManager stops removing/restoring instances of ChildItem (but continues to remove/restore instances of ParentItem). The issue goes away when I enclose the relevant code in ModelContext.transaction(block:). However, this shouldn't be necessary, as ModelContext.autosaveEnabled is true by default. The issues are occurring with Xcode 26.4 (17E192) and macOS Tahoe 26.4 (25E246). I have modified the macOS Document App project template to showcase the issue. The sample project, along with a screen recording of the crash, can be downloaded from here: https://drive.google.com/drive/folders/13bCB1qRZ6273BI81zW2zUUBraSvv6p5w?usp=share_link Is this expected behavior or should I file a bug report in Feedback Assistant? Steps to Reproduce To recreate the issue, follow these steps: Download and extract the "Xcode Project.zip" file linked above. Open the extracted "DocumentTest" project in Xcode. Build and run the "DocumentTest" app. In the document selection window, click "New Document" at the bottom-left. In the app, click the "+" button at the top-right to add a ParentItem with ChildItems. Click on the added ParentItem's button to add another ChildItem to it. Repeat steps 5–6 until you have 5 ParentItems with an additional ChildItem. Press Command-Z 10 times to undo all the changes. Press Command-Shift-Z 10 times to redo all the changes. Repeat steps 8–9 until UndoManager stops removing/restoring the additional ChildItem, and continue repeating them until the app eventually crashes (you may have to repeat them 5–10 times before the issue occurs). If you uncomment the ModelContext.transaction(block:) at line 13 of ContentView.swift and repeat the same steps above, no ChildItems will go missing and the app will not crash. Code ParentItem Model @Model final class ParentItem { var timestamp: Date @Relationship( deleteRule: .cascade, inverse: \ChildItem.parentItem ) var childItems: [ChildItem] = [] init(timestamp: Date) { self.timestamp = timestamp } } ChildItem Model @Model final class ChildItem { var index: Int var parentItem: ParentItem? init(index: Int) { self.index = index } } Creating, Inserting, and Linking ParentItem and ChildItem // Create and insert ParentItem let newParentItem = ParentItem( timestamp: Date() ) modelContext.insert(newParentItem) // Create and insert ChildItems var newChildItems: [ChildItem] = [] for index in 0..<Int.random(in: 2...8) { let newChildItem = ChildItem(index: index) newChildItems.append(newChildItem) modelContext.insert(newChildItem) } /* Establish relationship between ParentItem and ChildItems */ for newChildItem in newChildItems { newParentItem.childItems.append( newChildItem ) newChildItem.parentItem = newParentItem } Adding an Additional ChildItem to ParentItem // Uncommenting this block fixes the crash // try! modelContext.transaction { // Create and insert the new ChildItem let newChildItem = ChildItem( index: parentItem.childItems.count ) modelContext.insert(newChildItem) // Establish relationship to parentItem parentItem.childItems.append(newChildItem) newChildItem.parentItem = parentItem // }

Environment visionOS 26 Xcode 26 Issue I am experiencing crash when trying to access a [String] from a @Model data, after dismissing an immersiveSpace and opening a WindowGroup. This crash only occurs when trying to access the [String] property of my Model. It works fine with other properties. Thread 1: Fatal error: This backing data was detached from a context without resolving attribute faults: PersistentIdentifier(...) Steps to Reproduce Open WindowGroup Dismiss window, open ImmersiveSpace Dismiss ImmersiveSpace, reopen WindowGroup Any guidance would be appreciated! @main struct MyApp: App { var body: some Scene { WindowGroup(id: "main") { ContentView() } .modelContainer(for: [Item.self]) ImmersiveSpace(id: "immersive") { ImmersiveView() } } } // In SwiftData model @Model class Item { var title: String = "" // Accessing this property works fine var tags: [String] = [] @storageRestrictions(accesses: _$backingData, initializes: _tags) init(initialValue) { _$backingData.setValue(forKey: \. tags, to: initialValue) _tags =_ SwiftDataNoType() } get { _$observationRegistrar.access(self, keyPath: \.tags) **return self getValue(forkey: \.tags)** // Crashes here }

Testing Environment: iOS 18.4.1 / macOS 15.4.1 I am working on an iOS project that aims to utilize the user's iCloud Drive documents directory to save a specific directory-based file structure. Essentially, the app would create a root directory where the user chooses in iCloud Drive, then it would populate user generated files in various levels of nested directories. I have been attempting to use NSMetadataQuery with various predicates and search scopes but haven't been able to get it to directly monitor changes to files or directories that are not in the root directory. Instead, it only monitors files or directories in the root directory, and any changes in a subdirectory are considered an update to the direct children of the root directory. Example iCloud Drive Documents (Not app's ubiquity container) User Created Root Directory (Being monitored) File A Directory A File B An insertion or deletion within Directory A would only return a notification with userInfo containing data for NSMetadataQueryUpdateChangedItemsKey relating to Directory A, and not the file or directory itself that was inserted or deleted. (Query results array also only contain the direct children.) I have tried all combinations of these search scopes and predicates with no luck: query.searchScopes = [ rootDirectoryURL, NSMetadataQueryUbiquitousDocumentsScope, NSMetadataQueryAccessibleUbiquitousExternalDocumentsScope, ] NSPredicate(value: true) NSPredicate(format: "%K LIKE '*.md'", NSMetadataItemFSNameKey) NSPredicate(format: "%K BEGINSWITH %@", NSMetadataItemPathKey, url.path(percentEncoded: false)) I do see these warnings in the console upon starting my query: [CRIT] UNREACHABLE: failed to get container URL for com.apple.CloudDocs [ERROR] couldn't fetch remote operation IDs: NSError: Cocoa 257 "The file couldn’t be opened because you don’t have permission to view it." "Error returned from daemon: Error Domain=com.apple.accounts Code=7 "(null)"" But I am not sure what to make of that, since it does act normally for finding updates in the root directory. Hopefully this isn't a limitation of the API, as the only alternative I could think of would be to have multiple queries running for each nested directory that I needed updates for.

Hi, I am building an iOS app with SwiftUI and SwiftData for the first time and I am experiencing a lot of difficulty with this error: Thread 44: Fatal error: Never access a full future backing data - PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(backing: SwiftData.PersistentIdentifier.PersistentIdentifierBacking.managedObjectID(<ID> <x-coredata://<UUID>/MySwiftDataModel/p1>)), backing: SwiftData.PersistentIdentifier.PersistentIdentifierBacking.managedObjectID(<ID> <x-coredata://<UUID>/MySwiftDataModel/p1>)) with Optional(<UUID>) I have been trying to figure out what the problem is, but unfortunately I cannot find any information in the documentation or on other sources online. My only theory about this error is that it is somehow related to fetching an entity that has been created in-memory, but not yet saved to the modelContext in SwiftData. However, when I am trying to debug this, it's not clear this is the case. Sometimes the error happens, sometimes it doesn't. Saving manually does not always solve the error. Therefore, it would be extremely helpful if someone could explain what this error means and whether there are any best practices to do with SwiftData, or some pitfalls to avoid (such as wrapping my model context into a repository class). To be clear, this problem is NOT related to one area of my code, it happens throughout my app, at unpredictable places and time. Given that there is very little information related to this error, I am at a loss at how to make sure that this never happens. This question has been asked on the forum here as well as on StackOverflow, Reddit (can't link that here), but none of the answers worked for me. For reference, my models generally look like this: import Foundation import SwiftData @Model final class MySwiftDataModel { // Stable cross-device identity @Attribute(.unique) var uuid: UUID var someNumber: Int var someString: String @Relationship(deleteRule: .nullify, inverse: \AnotherSwiftDataModel.parentModel) var childModels: [AnotherSwiftDataModel] init(uuid: UUID = UUID(), someNumber: Int = 1, someString: String = "Some", childModels: [AnotherSwiftDataModel] = []) { self.uuid = uuid self.someNumber = someNumber self.someString = someString self.childModels = childModels } func addChildModel(model: AnotherSwiftDataModel) { self.childModels.append(model) } func removeChildModel(by id: PersistentIdentifier) { self.childModels = self.childModels.filter { $0.id != id } } } and the child model: import Foundation import SwiftData @Model final class AnotherSwiftDataModel { // Stable cross-device identity @Attribute(.unique) var uuid: UUID var someNumber: Int var someString: String var parentModel: MySwiftDataModel? init(uuid: UUID = UUID(), someNumber: Int = 1, someString: String = "Some") { self.uuid = uuid self.someNumber = someNumber self.someString = someString } } For now, you can assume I am not using CloudKit - i know for a fact the error is unrelated to CloudKit, because it happens when I am not using CloudKit (so I do not need to follow CloudKit's requirements for model design, such as nullable values etc). As I said, the error surfaces at different times - sometimes during assignments, a lot of times during deletions of related models, etc. Could you please explain what I am doing wrong and how I can make sure that this error does not happen? What are the architectural patterns that work best for SwiftData in this case? Do you have any examples of things I should avoid? Thanks

Hello, the last days I was trying to solve a bug in my Unit Tests related to the CoreData "NSManagedObjectContextObjectsDidChange" Notification. Im using some kind of Notification handler to save and abstract that for the UI and while the tests are running this notification was triggered with objects that doesn't exists anymore, which has resulted in a crash. After some debugging I have detected, that the objects in here are really old. The objects here was from few tests ago, where a Merge Conflict happened. In the meantime there was a plenty of resets and deletes of the whole db. I have also seen that the bad notification is the first in the stack trace of the main thread, which is in my opinion also not usual. So the real question is: The only difference what I have found for the bad notification to the real notification, was the existence of the key "NSObjectsChangedByMergeChangesKey" in the UserInfo dictionary of the ObjectsDidChange Notification. But this key is nowhere found in the documentation of Apple. Also the search engines does not produce any result. So what is this key and when is this key contained in this notification and when not? Maybe if I understand this, it helps me to understand the overall issue ...

Hi everyone, I’m facing an issue with CloudKit sync getting stuck during initial device migration in my SwiftData-based app. The app follows a local-first architecture using SwiftData + CloudKit sync, and works correctly for: ✔ Incremental sync ✔ Bi-directional updates ✔ Small datasets However, when onboarding a new device with large historical data, sync becomes extremely slow or appears stuck. Even after two hours data is not fully synced. ~6900 Transactions 🚨 Problem When installing the app on a new iPhone and enabling iCloud sync: • Initial hydration starts • A small amount of data syncs • Then sync stalls indefinitely Observed behaviour: • iPhone → Mac sync works (new changes sync back) • Mac → iPhone large historical migration gets stuck • Reinstalling app / clearing container does not resolve issue • Sync never completes full migration This gives the impression that: CloudKit is trickling data but not progressing after a certain threshold. The architecture is: • SwiftData local store • Manual CloudKit sync layer • Local-first persistence • Background push/pull sync So I understand: ✔ Conflict resolution is custom ✔ Initial import may not be optimized by default But I expected CloudKit to eventually deliver all records. Instead, the new device remains permanently in a “partial state”. ⸻ 🔍 Observations • No fatal CloudKit errors • No rate-limit errors • No quota issues • iCloud is available • Sync state remains “Ready” • Hydration remains “mostlyReady” Meaning: CloudKit does not report failure — but data transfer halts. ⸻ 🤔 Questions Would appreciate guidance on: Is CloudKit designed to support large initial dataset migration via manual sync layers? Or is this a known limitation vs NSPersistentCloudKitContainer? ⸻ Does CloudKit internally throttle historical record fetches? Could it silently stall without error when record volume is high? ⸻ Is there any recommended strategy for: • Bulk initial migration • Progressive hydration • Forcing forward sync progress ⸻ Should initial migration be handled outside CloudKit (e.g. via file transfer / backup restore) before enabling sync? ⸻ 🎯 Goal I want to support: • Large historical onboarding • Multi-device sync • User-visible progress Without forcing migration to Core Data. ⸻ 🙏 Any advice on: • Best practices • Debugging approach • CloudKit behavior in such scenarios would be greatly appreciated. Thank you!

I currently have a schema in production (cloudKit and local files) containing non-optional transformable values, e.g. @Attribute(.transformable(by: TestTransformer.self)) var number: TestTransformable = TestTransformable.init(value: 100) Unfortunately, this is preventing any migration from succeeding (documented at length in FB22151570). Briefly summarized, any migration from a Schema containing non-optional transformable values fails between willMigrate and didMigrate with the error "Can't find model for source store". This occurs for all migrations, including lightweight with a migration plan, lightweight without a plan, and custom migrations. Worst of all, this also prevents migration to optional transformable values, or the elimination of the transformable value entirely, leaving us completely stuck. (note: optional transformable values only work when they have a default value set to nil, otherwise even these have issues migrating) We already have features being blocked by this issue, and would like to preserve user-data while restoring our ability to move forwards with database. Are there any known workarounds for using SwiftData (+CloudKit) when schema migration is non-operational?

I have implemented CKSyncEngine synchronization, and it works well. I can update data on one device and see the changes propagate to another device quickly. However, the initial sync when a user downloads the app on a new device is a significant issue for both me and my users. One problem is that the sync engine fetches deletion events from the server. On a new device, the local database is empty, so these deletions are essentially no-ops. This would not be a big problem if there were only a few records or if it was fast. I measured the initial sync and found that there are 150 modified records and 62,168 deletions. Counting these alone takes over five minutes, even without processing them. The deletions do nothing because the local database has nothing to delete, yet they still add a significant delay. I understand that the sync engine ensures consistency across all devices, but five minutes of waiting with the app open just to insert a small number of records is excessive. The problem would be worse if there were tens of thousands of new records to insert, since downloading and saving the data would take even longer. This leads to a poor user experience. Users open the app and see data being populated for several minutes, or they are stuck on a screen that says the data is being synchronized with iCloud. I am wondering if there is a way to make the sync engine ignore deletion events when the state serialization is nil. Alternatively, is there a recommended method for handling initial synchronization more efficiently? One idea I considered is storing all the data as a backup in iCloud Documents, along with the state serialization at that point in time. When a user opens the app for the first time, I could download the file, extract the data, and set the state serialization to the saved value. I am not sure if this would work. I do not know if state serialization is tied to the device or if it only represents the point where the sync engine left off. My guess is that it might reference some local device storage. I am not sure what else to try. I could fetch all data using CloudKit, create the sync engine with an empty state serialization, and let it fetch everything again, but that would still take a long time. My records are very small, mostly a date when something happened and an ID referencing the parent. Since the app tracks watched episodes, I only store the date the user watched the episode and the ID of that episode.

Hello everyone, I'm trying to adopt the new Staged Migrations for Core Data and I keep running into an error that I haven't been able to resolve. The error messages are as follows: warning: Multiple NSEntityDescriptions claim the NSManagedObject subclass 'Movie' so +entity is unable to disambiguate. warning: 'Movie' (0x60000350d6b0) from NSManagedObjectModel (0x60000213a8a0) claims 'Movie'. error: +[Movie entity] Failed to find a unique match for an NSEntityDescription to a managed object subclass This happens for all of my entities when they are added/fetched. Movie is an abstract entity subclass, and it has the error error: +[Movie entity] Failed to find which is unique to the subclass entities, but this occurs for all entities. The NSPersistentContainer is loaded only once, and I set the following option after it's loaded: storeDescription.setOption( [stages], forKey: NSPersistentStoreStagedMigrationManagerOptionKey ) The warnings and errors only appear after I fetch or save to context. It happens regardless of whether the database was migrated or not. In my test project, using the generic NSManagedObject with NSEntityDescription.insertNewObject(forEntityName: "MyEntity", into: context) does not cause the issue. However, using the generic NSManagedObject is not a viable option for my app. Setting the module to "Current Project Module" doesn't change anything, except that it now prints "claims 'MyModule.Show'" in the warnings. I have verified that there are no other entities with the same name or renameIdentifier. Has anyone else encountered this issue, or can offer any suggestions on how to resolve it? Thanks in advance for any help!

When creating a new project in Xcode 26, the default for defaultIsolation is MainActor. Core Data creates classes for each entity using code gen, but now those classes are also internally marked as MainActor, which causes issues when accessing managed object from a background thread like this. Is there a way to fix this warning or should Xcode actually mark these auto generated classes as nonisolated to make this better? Filed as FB13840800. nonisolated struct BackgroundDataHandler { @concurrent func saveItem() async throws { let context = await PersistenceController.shared.container.newBackgroundContext() try await context.perform { let newGame = Item(context: context) newGame.timestamp = Date.now // Main actor-isolated property 'timestamp' can not be mutated from a nonisolated context; this is an error in the Swift 6 language mode try context.save() } } } Turning code gen off inside the model and creating it manually, with the nonisolated keyword, gets rid of the warning and still works fine. So I guess the auto generated class could adopt this as well? public import Foundation public import CoreData public typealias ItemCoreDataClassSet = NSSet @objc(Item) nonisolated public class Item: NSManagedObject { }

Hi, Not sure how to describe my issue best: I am using SwiftData and CloudKit to store my data. In the past, when I tested my app on different devices, the data would sync between the devices automatically. For whatever reason this has stopped now and the data no longer syncs. No matter what I do, it feels as if all the data is actually stored just locally on each device. How can I check if the data is actually stored in the cloud and what could be reasons, why its no longer synching between my devices (and yes, I am logged in with the same Apple ID on all devices). Thanks for any hint! Max

I'm testing CloudKit Sharing (CKShare) in my app. My app uses CloudKit Sharing to share private data between users (this is not App Store Family Sharing or purchase sharing, it's app-level sharing via CKShare). To properly test this, I need three or four Apple Accounts with distinct roles in my app. This means I need three/four separate iCloud accounts signed in on test devices. Simulators are probably ok: two acting as "parents" (share owner and participant): parent1.sandbox@example.com parent2.sandbox@example.com, one or two as a "child" (participant) child1.sandbox@example.com child2.sandbox@example.com except obviously using my domain name. I attempted to create Sandbox Apple Accounts in App Store Connect, but these don't appear to work with CloudKit Sharing. I then created several standard Apple Accounts, but I've now hit a limit — I believe my mobile number (used for two-factor authentication on the test accounts) has been flagged or rate-limited for account creation, and I can no longer create or verify new accounts with it. It's also blocked the email addresses associated with those accounts from being used for new account creation. Can Apple or anyone advise on the recommended approach for testing CloudKit Sharing with multiple participants? are Sandbox accounts supposed to work for CKShare, or do I need full Apple Accounts? How do i create and verify these in the correct way to avoid hitting these limits or breaking terms of service?

My Code: let op = CKModifyRecordsOperation(recordIDsToDelete:recordIDsToDelete) op.modifyRecordsCompletionBlock = { _, deleteRecordIDs, error in if error == nil { print("successful delete deleteRecordIDS = \(deleteRecordIDs)") } else { print("delete error = \(error?.localizedDescription)") } } op.database = CKContainer.default().privateCloudDatabase op.qualityOfService = .userInitiated CKContainer.default().privateCloudDatabase.add(op) My problem is that CKRecord are not deleted once I reinstall the app: when I reinstall the app and try to delete a CloudKit record, the method is executed successfully (error is nil) but the records are still in CloudKit Dashboards.

I work on an app that saves data to the Documents folder in the users iCloud Drive. This uses the iCloud -> iCloud Documents capability with a standard container. We've noticed an issue where a user will delete the apps data by doing to Settings > {Name} > iCloud > Storage > App Name > select "delete data from iCloud", and then our app can no longer write to or create the Documents folder. Once that happens, we get this error: Error Domain=NSCocoaErrorDomain Code=513 "You don't have permission to save the file "Documents" in the folder "iCloud~your~bundle~identifier"." UserInfo={NSFilePath=/private/var/mobile/Library/Mobile Documents/iCloud~your~bundle~identifier/Documents, NSURL=file:///private/var/mobile/Library/Mobile%20Documents/iCloud~your~bundle~identifier/Documents, NSUnderlyingError=0x1102c7ea0 {Error Domain=NSPOSIXErrorDomain Code=13 "Permission denied"}} This is reproducible using the sample project here https://developer.apple.com/documentation/uikit/synchronizing-documents-in-the-icloud-environment. Steps to reproduce in that project: Tap the plus sign in the top right corner to create a new document Add a document name and tap "Save to Documents" Go to Settings > {Name} > iCloud > Storage > SimpleiCloudDocument App Name > select "delete data from iCloud" Reopen the app and repeat steps 1-2 Observe error on MainViewController+Document.swift:59 Deleting and reinstalling the app doesn't seem to help.

I'm experiencing a critical issue with SwiftData custom migrations where objects created during migration appear to be inserted successfully but aren't persisted or found by queries after migration completes. The migration logs show objects being created, but subsequent queries return zero results. I'm migrating from schema version V2 to V2_5, which involves: Renaming Person class to GroupData Keeping the same data structure but changing the class name while keeping the old class. Using a custom migration stage to copy data from old to new schema Below is an extract of my two schema and migration plan: Environment: Xcode 16.0, iOS 18.0, Swift 6.0 SchemaV2 enum LinkMapV2: VersionedSchema { static let versionIdentifier: Schema.Version = .init(2, 0, 0) static var models: [any PersistentModel.Type] { [AnnotationData.self, Person.self, History.self] } @Model final class Person { @Attribute(.unique) var id: UUID var name: String var photo: String var requirement: String var statue: Bool var annotationId: UUID? var number: Int = 0 init(id: UUID = UUID(), name: String = "", photo: String = "", requirement: String = "", status: Bool = false, annotationId: UUID? = nil, number: Int = 0) { self.id = id self.name = name self.photo = photo self.requirement = requirement self.statue = status self.annotationId = annotationId self.number = number } } } Schema V2_5 static let versionIdentifier: Schema.Version = .init(2, 5, 0) static var models: [any PersistentModel.Type] { [AnnotationData.self, Person.self, GroupData.self, History.self] } // Keep the old Person model for migration @Model final class Person { @Attribute(.unique) var id: UUID var name: String var photo: String var requirement: String var statue: Bool var annotationId: UUID? var number: Int = 0 init(id: UUID = UUID(), name: String = "", photo: String = "", requirement: String = "", status: Bool = false, annotationId: UUID? = nil, number: Int = 0) { self.id = id self.name = name self.photo = photo self.requirement = requirement self.statue = status self.annotationId = annotationId self.number = number } } // Add the new GroupData model that mirrors Person @Model final class GroupData { @Attribute(.unique) var id: UUID var name: String var photo: String var requirement: String var status: Bool var annotationId: UUID? var number: Int = 0 init(id: UUID = UUID(), name: String = "", photo: String = "", requirement: String = "", status: Bool = false, annotationId: UUID? = nil, number: Int = 0) { self.id = id self.name = name self.photo = photo self.requirement = requirement self.status = status self.annotationId = annotationId self.number = number } } } Migration Plan static let migrationV2toV2_5 = MigrationStage.custom( fromVersion: LinkMapV2.self, toVersion: LinkMapV2_5.self, willMigrate: { context in do { let persons = try context.fetch(FetchDescriptor<LinkMapV2.Person>()) print("=== MIGRATION STARTED ===") print("Found \(persons.count) Person objects to migrate") guard !persons.isEmpty else { print("No Person data requires migration") return } for person in persons { print("Migrating Person: '\(person.name)' with ID: \(person.id)") let newGroup = LinkMapV2_5.GroupData( id: person.id, // Keep the same ID name: person.name, photo: person.photo, requirement: person.requirement, status: person.statue, annotationId: person.annotationId, number: person.number ) context.insert(newGroup) print("Inserted new GroupData: '\(newGroup.name)'") // Don't delete the old Person yet to avoid issues // context.delete(person) } try context.save() print("=== MIGRATION COMPLETED ===") print("Successfully migrated \(persons.count) Person objects to GroupData") } catch { print("=== MIGRATION ERROR ===") print("Migration failed with error: \(error)") } }, didMigrate: { context in do { // Verify migration in didMigrate phase let groups = try context.fetch(FetchDescriptor<LinkMapV2_5.GroupData>()) let oldPersons = try context.fetch(FetchDescriptor<LinkMapV2_5.Person>()) print("=== MIGRATION VERIFICATION ===") print("New GroupData count: \(groups.count)") print("Remaining Person count: \(oldPersons.count)") // Now delete the old Person objects for person in oldPersons { context.delete(person) } if !oldPersons.isEmpty { try context.save() print("Cleaned up \(oldPersons.count) old Person objects") } // Print all migrated groups for debugging for group in groups { print("Migrated Group: '\(group.name)', Status: \(group.status), Number: \(group.number)") } } catch { print("Migration verification error: \(error)") } } ) And I've attached console output below: Console Output

When I query, an existing database with over 10,000 records from an Objective C app (i.e. CKQueryOperation) I get only N x 100 records returned where N varies each time between 0 and about 10 (i.e. never more than 1000 records and always an even multiple of 100). When I do a “Query Records” on the CloudKit Dashboard I get a similar number of pages of records downloaded (i.e. 0-10). If I tap “Query Records” multiple times I will get more pages of records until the full 10,000 are downloaded. This had been working fine until recently, both from the app and the Dashboard. There are multiple Record Types in the database. Only one Record Type is erroring. The other Record Types continue to work both from the app and the Dashboard. In particular, the Users Record Type has many many records and they all download to many pages with a single tap of “Query Records”. I have posted this to the Feedback Assistant under FB22358865. Here is my code: NSPredicate *predicate =[NSPredicate predicateWithFormat:@"modificationDate>%@",dateLastSynched]; CKRecordType theRecordName=[NSString stringWithString:@"Notices”]; // I also try this for @“Links” and @“Messages” and @“EventMessages" CKQuery *query = [[CKQuery alloc] initWithRecordType:theRecordName predicate:predicate]; CKQueryOperation *theOperation=[[CKQueryOperation alloc] initWithQuery:query]; [self startAQueryOperation:(CKQueryOperation *)theOperation theName:(NSString *)recordName]; -(void)startAQueryOperation:(CKQueryOperation *)theOperation theName:(NSString *)recordName{ theOperation.recordFetchedBlock=^(CKRecord *theRecord){ NSLog(@"XXXjust downloaded a %@",recordName); }; theOperation.queryCompletionBlock=^(CKQueryCursor *theCursor, NSError *error){ if(error){ NSLog(@"XXXerror %@",error); } if(theCursor){ CKQueryOperation *anotherOperation=[[CKQueryOperation alloc] initWithCursor:theCursor]; [self startAQueryOperation:anotherOperation theName:recordName]; } }; CKDatabase *publicDatabase = [[CKContainer defaultContainer] publicCloudDatabase]; [publicDatabase addOperation:theOperation]; } When I run this code in the app I get no “XXXerror” from the NSLogs. I get the expected number of “XXXjust downloaded a” EventMessages (435) and Messages (594) and Links (15) but I get varying amounts, 100 or 400 or 500 “xxjust downloaded a” for the Notices when I should get 10,118 records. Thinking that 10,000 records is too much, if I alter “dateLastSynched” for Notices I still get only 100 or 200, not the expected number. Note that the number is always a multiple of 100. This seems to be consistent with the typical number of records I get on the CloudKit dashboard each time I tap “Query Records”.

Our app saves its data to iCloud by default. In most cases, this is working as intended & the data can be synced across devices with no problems. But recently, in testing, we discovered a situation where it's possible to save data before the NSMetadataQuery finishes & starts downloading the cloud files. When this happens, the query will then finish, and return the NEW file (with no other versions or conflicts). Is there a way to ensure that writing a file (version A) to ubiquitous storage when another version (version B) exists in the cloud is treated as a conflict, rather than just stomping all over the other version? I've tried querying the file metadata for the file URL (NSURLIsUbiquitousItemKey, NSMetadataUbiquitousItemDownloadingStatusKey, NSURLUbiquitousItemDownloadRequestedKey, NSURLUbiquitousItemHasUnresolvedConflictsKey) before saving, but it just returns nil.

I'm developing an app that uses CloudKit synchronization with SwiftData and on visionOS I added an App Settings bundle. I have noticed that sometimes, when the app is open and the user changes a setting from the App Settings bundle, the following fatal error occurs: SwiftData/BackingData.swift:831: Fatal error: This model instance was destroyed by calling ModelContext.reset and is no longer usable. The setting is read within the App struct in the visionOS app target using @AppStorage and this value is in turn used to set the passthrough video dimming via the .preferredSurroundingsEffect modifier. The setting allows the user to specify the dimming level as dark, semi dark, or ultra dark. The fatal error appears to occur intermittently although the first time it was observed was after adding the settings bundle. As such, I suspect there is some connection between those code changes and this fatal error even though they do not directly relate to SwiftData.

I'm working on a macOS app with a Safari web extension. I'm trying to share a SwiftData model between devices using CloudKit synchronization. I am able to get synchronization in the main app on the same device, CloudKit sync works correctly — changes appear in the CloudKit Dashboard under com.apple.coredata.cloudkit.zone. However, in the Safari App Extension, data is saved locally and persists across launches, but never syncs to CloudKit. I have followed the recommended practices for configuring the App Group and entitlements, but the issue persists. Questions: Is there an official limitation preventing Safari App Extensions from connecting to the CloudKit daemon (cloudd)? If not, what entitlements or configuration changes are required for a Safari App Extension to successfully sync with CloudKit? Is the xpc_error=159 from bootstrap_look_up() a known sandbox restriction for this extension type? Any guidance from Apple engineers or others who have successfully used CloudKit from a Safari App Extension would be appreciated. What I’ve confirmed: The extension’s .entitlements includes: com.apple.security.app-sandbox com.apple.developer.icloud-services CloudKit com.apple.developer.icloud-container-identifiers iCloud.dev.example.myapp Same iCloud container ID for both app and extension CloudKit container exists and is initialized in CloudKit Console Running in :Sandbox environment during development Database name in SwiftData matches container identifier (without the iCloud. prefix) The extension’s codesign output shows correct entitlements App Group is configured (although in this case, extension and app use separate stores intentionally) Observed behavior in Console.app logs: CloudKit sync engine initializes in the extension XPC activities are registered for import/export: _xpc_activity_register: com.apple.coredata.cloudkit.activity.export. xpc_activity_set_criteria: ... import. Then a bootstrap lookup fails: failed to do a bootstrap look-up: xpc_error=[159: Unknown error: 159] CloudKit daemon connection error: CKErrorDomain Code=6 "Error connecting to CloudKit daemon" NSCocoaErrorDomain Code=4099 There is no “Will attempt to upload transactions” or “Upload succeeded” logs are ever seen. Symptoms When the extension is run, I see logs like the following in Console.app: [0x13e215820] failed to do a bootstrap look-up: xpc_error=[159: Unknown error: 159] CoreData+CloudKit: -[PFCloudKitSetupAssistant _checkAccountStatus:]_block_invoke(342): Fetched account info for store : (null) Error Domain=CKErrorDomain Code=6 "Error connecting to CloudKit daemon. This could happen for many reasons..."

We are seeing a CloudKit private database failure for this specific container: iCloud.com.matrixqlc.photodiet.sync Failure pattern: accountStatus succeeds in some cases ensure/create custom zone succeeds but record/database-level operations consistently fail with: CKErrorDomain code = 15 CKInternalErrorDomain code = 2000 HTTP 500 Failing operations include: allRecordZones() databaseChanges(since:nil) allSubscriptions() fetch record zone metadata save record fetch record query records What makes this unusual is that the issue follows the container, not the app. On the same physical device, same Apple ID, same developer team: PhotoDiet + iCloud.com.matrixqlc.photodiet.sync => fails RepaymentCalculator + iCloud.com.matrixqlc.photodiet.sync => fails PhotoDiet + iCloud.com.matrixqlc.repaymentcalculator.sync2 => succeeds RepaymentCalculator + iCloud.com.matrixqlc.repaymentcalculator.sync2 => succeeds So this does not currently look like: app-specific entitlement/provisioning issues device/account issues CloudKit API misuse in one app record schema or app business logic issues It currently looks like the container iCloud.com.matrixqlc.photodiet.sync itself may be in a bad backend state. Sample request identifiers: RequestUUID: C8403047-0037-4D36-A7A7-CF3C83584A42 RequestUUID: 04437D9D-115E-45F5-87B5-A8CD146AE705 RequestUUID: C924B620-BAEE-403D-B944-151ADCF3419F RequestUUID: A54E79E1-6037-4533-BA09-18FBC436851C RequestUUID: 3EFD8913-3781-47CF-A48C-B651BF38EA50 RequestUUID: 2677A991-40B3-42AB-9CE5-3C4F1288EE08 Feedback Assistant ID: FB22539748 Has anyone seen a container-specific CloudKit private database failure like this, where multiple apps under the same team can access one container normally but consistently fail on another container with CKError 15 / HTTP 500?