Hi, I did cloudkit synchronization using swiftdata. However, synchronization does not occur automatically, and synchronization occurs intermittently only when the device is closed and opened. For confirmation, after changing the data in Device 1 (saving), when the data is fetched from Device 2, there is no change. I've heard that there's still an issue with swiftdata sync and Apple is currently troubleshooting it, is the phenomenon I'm experiencing in the current version normal?

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..."

LSUB always returns all the subscribed folders. For example lsub "" "test/*" returns a list of all the folders and not just subscribed folders that are subfolders of test. I.e, it returns the same folder list as lsub "" "*". For more details please see https://bugzilla.mozilla.org/show_bug.cgi?id=1817707#c15

I am trying to add a custom JSON DataStore and DataStoreConfiguration for SwiftData. Apple kindly provided some sample code in the WWDC24 session, "Create a custom data store with SwiftData", and (once updated for API changes since WWDC) that works fine. However, when I try to add a relationship between two classes, it fails. Has anyone successfully made a JSONDataStore with a relationship? Here's my code; firstly the cleaned up code from the WWDC session: import SwiftData final class JSONStoreConfiguration: DataStoreConfiguration { typealias Store = JSONStore var name: String var schema: Schema? var fileURL: URL init(name: String, schema: Schema? = nil, fileURL: URL) { self.name = name self.schema = schema self.fileURL = fileURL } static func == (lhs: JSONStoreConfiguration, rhs: JSONStoreConfiguration) -> Bool { return lhs.name == rhs.name } func hash(into hasher: inout Hasher) { hasher.combine(name) } } final class JSONStore: DataStore { typealias Configuration = JSONStoreConfiguration typealias Snapshot = DefaultSnapshot var configuration: JSONStoreConfiguration var name: String var schema: Schema var identifier: String init(_ configuration: JSONStoreConfiguration, migrationPlan: (any SchemaMigrationPlan.Type)?) throws { self.configuration = configuration self.name = configuration.name self.schema = configuration.schema! self.identifier = configuration.fileURL.lastPathComponent } func save(_ request: DataStoreSaveChangesRequest<DefaultSnapshot>) throws -> DataStoreSaveChangesResult<DefaultSnapshot> { var remappedIdentifiers = [PersistentIdentifier: PersistentIdentifier]() var serializedData = try read() for snapshot in request.inserted { let permanentIdentifier = try PersistentIdentifier.identifier(for: identifier, entityName: snapshot.persistentIdentifier.entityName, primaryKey: UUID()) let permanentSnapshot = snapshot.copy(persistentIdentifier: permanentIdentifier) serializedData[permanentIdentifier] = permanentSnapshot remappedIdentifiers[snapshot.persistentIdentifier] = permanentIdentifier } for snapshot in request.updated { serializedData[snapshot.persistentIdentifier] = snapshot } for snapshot in request.deleted { serializedData[snapshot.persistentIdentifier] = nil } try write(serializedData) return DataStoreSaveChangesResult<DefaultSnapshot>(for: self.identifier, remappedIdentifiers: remappedIdentifiers) } func fetch<T>(_ request: DataStoreFetchRequest<T>) throws -> DataStoreFetchResult<T, DefaultSnapshot> where T : PersistentModel { if request.descriptor.predicate != nil { throw DataStoreError.preferInMemoryFilter } else if request.descriptor.sortBy.count > 0 { throw DataStoreError.preferInMemorySort } let objs = try read() let snapshots = objs.values.map({ $0 }) return DataStoreFetchResult(descriptor: request.descriptor, fetchedSnapshots: snapshots, relatedSnapshots: objs) } func read() throws -> [PersistentIdentifier : DefaultSnapshot] { if FileManager.default.fileExists(atPath: configuration.fileURL.path(percentEncoded: false)) { let decoder = JSONDecoder() decoder.dateDecodingStrategy = .iso8601 let data = try decoder.decode([DefaultSnapshot].self, from: try Data(contentsOf: configuration.fileURL)) var result = [PersistentIdentifier: DefaultSnapshot]() data.forEach { s in result[s.persistentIdentifier] = s } return result } else { return [:] } } func write(_ data: [PersistentIdentifier : DefaultSnapshot]) throws { let encoder = JSONEncoder() encoder.dateEncodingStrategy = .iso8601 encoder.outputFormatting = [.prettyPrinted, .sortedKeys] let jsonData = try encoder.encode(data.values.map({ $0 })) try jsonData.write(to: configuration.fileURL) } } The data model classes: import SwiftData @Model class Settings { private(set) var version = 1 @Relationship(deleteRule: .cascade) var hack: Hack? = Hack() init() { } } @Model class Hack { var foo = "Foo" var bar = 42 init() { } } Container: lazy var mainContainer: ModelContainer = { do { let url = // URL to file let configuration = JSONStoreConfiguration(name: "Settings", schema: Schema([Settings.self, Hack.self]), fileURL: url) return try ModelContainer(for: Settings.self, Hack.self, configurations: configuration) } catch { fatalError("Container error: \(error.localizedDescription)") } }() Load function, that saves a new Settings JSON file if there isn't an existing one: @MainActor func loadSettings() { let mainContext = mainContainer.mainContext let descriptor = FetchDescriptor<Settings>() let settingsArray = try? mainContext.fetch(descriptor) print("\(settingsArray?.count ?? 0) settings found") if let settingsArray, let settings = settingsArray.last { print("Loaded") } else { let settings = Settings() mainContext.insert(settings) do { try mainContext.save() } catch { print("Error saving settings: \(error)") } } } The save operation creates a JSON file, which while it isn't a format I would choose, is acceptable, though I notice that the "hack" property (the relationship) doesn't have the correct identifier. When I run the app again to load the data, I get an error (that there wasn't room to include in this post). Even if I change Apple's code to not assign a new identifier, so the relationship property and its pointee have the same identifier, it still doesn't load. Am I doing something obviously wrong, or are relationships not supported in custom data stores?

I have a ModelActor that creates a hierarchy of models and returns a PersistentIdentifier for the root. I'd like to do that in a transaction, but I don't know of a good method of getting that identifier if the models are created in a transaction. For instance, an overly simple example: func createItem(timestamp: Date) throws -> PersistentIdentifier { try modelContext.transaction { let item = Item(timestamp: timestamp) modelContext.insert(item) } // how to return item.persistentModelID? } I can't return the item.persistentModelID from the transaction closure and even if I could, it will be a temporary ID until after the transaction is executed. I can't create the Item outside the transaction and just have the transaction do an insert because swift will raise a data race error if you then try to return item.persistentModelID. Is there any way to do this besides a modelContext.fetch* with separate unique identifiers?

I am using SwiftData with CloudKit to synchronize data across multiple devices, and I have encountered an issue: occasionally, abnormal sync behavior occurs between two devices (it does not happen 100% of the time—only some users have reported this problem). It seems as if synchronization between the two devices completely stops; no matter what operations are performed on one end, the other end shows no response. After investigating, I suspect the issue might be caused by both devices simultaneously modifying the same field, which could lead to CloudKit's logic being unable to handle such conflicts and causing the sync to stall. Are there any methods to avoid or resolve this situation? Of course, I’m not entirely sure if this is the root cause. Has anyone encountered a similar issue?

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.

Hi everyone, I've recently implemented CKSyncEngine in my app, and I have two questions regarding its behavior: Duplicate FetchedRecordZoneChanges After Sending Changes: I’ve noticed that the engine sometimes receives a FetchedRecordZoneChanges event containing modifications and deletions that were just sent by the same device a few moments earlier. This event arrives after the SentRecordZoneChanges event, and both events share the same recordChangeTag, which results in double-handling the record. Is this expected behavior? I’d like to confirm if this is how CKSyncEngine works or if I might be overlooking something. Handling Initial Sync with a "Sync Screen": When a user opens the app for the first time and already has data stored in iCloud, I need to display a "Sync Screen" temporarily to prevent showing partial data or triggering abrupt, rapid UI changes. I’ve found that canceling current operations, then awaiting sendChanges() and fetchChanges() works well to ensure data is fully synced before dismissing the sync screen: displaySyncScreen = true await syncEngine.cancelOperations() try await syncEngine.sendChanges() try await syncEngine.fetchChanges() displaySyncScreen = false However, I’m unsure if canceling operations like this could lead to data loss or other issues. Is this a safe approach, or would you recommend a better strategy for handling this initial sync state?

I'm trying to handle the serverRecordChanged return code you get in CKError when you have a conflict and your using the savePolicy of ifServerRecordUnchanged. According to the CKError.Code.serverRecordChanged documentation, I should be receiving all three records that I need to do a 3-way merge. The problem is that the ancestorRecord (CKRecordChangedErrorAncestorRecordKey can also be used to look it up in the userInfo) doesn't actually contain a record. It only contains the record metadata. Is there something I need to be doing to get the full ancestorRecord in the CKError? If not is it possible to query iCloud for the ancestorRecord? Given that iCloud has the change history (as I understand it), then it is theoretically possible. I just don't know how to do it if it is possible. Are 3-way merges even possible? The design of the serverRecordChanged looks like that is the intent, but I can't see how to do it with the data that CloudKit is providing.

Users have been reporting that the TestFlight version of my app (compiled with Xcode 26 Beta 6 17A5305f) is sometimes crashing on startup. Upon investigating their ips files, it looks like Core Data is locking up internally during its initialization, resulting in iOS killing my app. I have not recently changed my Core Data initialization logic, and it's unclear how I should proceed. Is this a known issue? Any recommended workaround? I have attached the crash stack below. Thanks! crash_log.txt

Hello Apple Team, We’re building a CloudKit-enabled Core Data app and would like clarification on the behavior and performance characteristics of Binary Data attributes with “Allows External Storage” enabled when used with NSPersistentCloudKitContainer. Initially, we tried storing image files manually on disk and only saving the metadata (file URLs, dimensions, etc.) in Core Data. While this approach reduced the size of the Core Data store, it introduced instability after app updates and broke sync between devices. We would prefer to use the official Apple-recommended method and have Core Data manage image storage and CloudKit syncing natively. Specifically, we’d appreciate guidance on the following: When a Binary Data attribute is marked as “Allows External Storage”, large image files are stored as separate files on device rather than inline in the SQLite store. How effective is this mechanism in keeping the Core Data store size small on device? Are there any recommended size thresholds or known limits for how many externally stored blobs can safely be managed this way? How are these externally stored files handled during CloudKit sync? Does each externally stored Binary Data attribute get mirrored to CloudKit as a CKAsset? Does external storage reduce the sync payload size or network usage, or is the full binary data still uploaded/downloaded as part of the CKAsset? Are there any bandwidth implications for users syncing via their private CloudKit database, versus developer costs in the public CloudKit database? Is there any difference in CloudKit or Core Data behavior when a Binary Data attribute is managed this way versus manually storing image URLs and handling the file separately on disk? Our goal is to store user-generated images efficiently and safely sync them via CloudKit, without incurring excessive local database bloat or CloudKit network overhead. Any detailed guidance or internal performance considerations would be greatly appreciated. Thank you, Paul Barry Founder & Lead Developer — Boat Buddy / Vessel Buddy iOS App Archipelago Environmental Solutions Inc.

I'm using NSPersistentCloudKitContainer with Core Data and I receive errors because my iCloud space is full. The errors printed are the following: <CKError 0x280df8e40: "Quota Exceeded" (25/2035); server message = "Quota exceeded"; op = 61846C533467A5DF; uuid = 6A144513-033F-42C2-9E27-693548EF2150; Retry after 342.0 seconds>. I want to inform the user about this issue, but I can't find a way to access the details of the error. I'm listening to NSPersistentCloudKitContainer.eventChangedNotification, I receive a error of type .partialFailure. But when I want to access the underlying errors, the partialErrorsByItemID property on the error is nil. How can I access this Quota Exceeded error? import Foundation import CloudKit import Combine import CoreData class SyncMonitor { fileprivate var subscriptions = Set<AnyCancellable>() init() { NotificationCenter.default.publisher(for: NSPersistentCloudKitContainer.eventChangedNotification) .sink { notification in if let cloudEvent = notification.userInfo?[NSPersistentCloudKitContainer.eventNotificationUserInfoKey] as? NSPersistentCloudKitContainer.Event { guard let ckerror = cloudEvent.error as? CKError else { return } print("Error: \(ckerror.localizedDescription)") if ckerror.code == .partialFailure { guard let errors = ckerror.partialErrorsByItemID else { return } for (_, error) in errors { if let currentError = error as? CKError { print(currentError.localizedDescription) } } } } } // end of sink .store(in: &subscriptions) } }

Is there a way to view the data saved when using swiftdata? Even after deleting all models, the storage space taken up by the app in Settings is too large.

I'm writing some tests to confirm the behavior of my app. White creating a model actor to delete objects I realized that ModelContext.model(for:) does return objects that are deleted. I was able to reproduces this with this minimal test case: @Model class Activity { init() {} } struct MyLibraryTests { let modelContainer = try! ModelContainer( for: Activity.self, configurations: ModelConfiguration( isStoredInMemoryOnly: true ) ) init() throws { let context = ModelContext(modelContainer) context.insert(Activity()) try context.save() } @Test func modelForIdAfterDelete() async throws { let context = ModelContext(modelContainer) let id = try context.fetch(FetchDescriptor<Activity>()).first!.id context.delete(context.model(for: id) as! Activity) try context.save() let result = context.model(for: id) as? Activity #expect(result == nil) // Expectation failed: (result → MyLibrary.Activity) == nil } @Test func fetchDescriptorAfterDelete() async throws { let context = ModelContext(modelContainer) let id = try context.fetch(FetchDescriptor<Activity>()).first!.id context.delete(context.model(for: id) as! Activity) try context.save() let result = try context.fetch( FetchDescriptor<Activity>(predicate: #Predicate { $0.id == id }) ).first #expect(result == nil) } } Here I create a new context, insert an model and save it. The test modelForIdAfterDelete does fail, as result still contains the deleted object. I also tried to check #expect(result!.isDeleted), but it is also false. With the second test I use a FetchDescriptor to retrieve the object by ID and it correctly returns nil. Shouldn't both methods use a consistent behavior?

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 have an Apple app that uses SwiftData and icloud to sync the App's data across users' devices. Everything is working well. However, I am facing the following issue: SwiftData does not support public sharing of the object graph with other users via iCloud. How can I overcome this limitation without stopping using SwiftData? Thanks in advance!

My use case is the following: Every user of my app can create as an owner a set of items.  These items are private until the owner invites other users to share all of them as participant. The participants can modify the shared items and/or add other items. So, sharing is not done related to individual items, but to all items of an owner. I want to use CoreData & CloudKit to have local copies of private and shared items. To my understanding, CoreData & CloudKit puts all mirrored items in a special zone „com.apple.coredata.cloudkit.zone“. So, this zone should be shared, i.e. all items in it. In the video it is said that NSPersistentCloudKitContainer uses Record Zone Sharing optionally in contrast to hierarchically record sharing using a root record. But how is this done? Maybe I can declare zone „com.apple.coredata.cloudkit.zone“ as a shared zone?

I have been working on an app for the past few months, and one issue that I have encountered a few times is an error where quick subsequent deletions cause issues with detached tasks that are triggered from some user actions. Inside a Task.detached, I am building an isolated model context, querying for LineItems, then iterating over those items. The crash happens when accessing a Transaction property through a relationship. var byTransactionId: [UUID: [LineItem]] { return Dictionary(grouping: self) { item in item.transaction?.id ?? UUID() } } In this case, the transaction has been deleted, but the relationship existed when the fetch occurred, so the transaction value is non-nil. The crash occurs when accessing the id. This is the error. SwiftData/BackingData.swift:1035: Fatal error: This model instance was invalidated because its backing data could no longer be found the store. PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(backing: SwiftData.PersistentIdentifier.PersistentIdentifierBacking.managedObjectID(0xb43fea2c4bc3b3f5 &lt;x-coredata://A9EFB8E3-CB47-48B2-A7C4-6EEA25D27E2E/Transaction/p1756&gt;))) I see other posts about this error and am exploring some suggestions, but if anyone has any thoughts, they would be appreciated.

我正在使用 Core Data 开发一个 SwiftUI 项目。我的数据模型中有一个名为 AppleUser 的实体，具有以下属性：id （UUID）、name （String）、email （String）、password （String） 和 createdAt （Date）。所有属性都是非可选的。 我使用 Xcode 的自动生成创建了相应的 Core Data 类文件（AppleUser+CoreDataClass.swift 和 AppleUser+CoreDataProperties.swift）。我还有一个 PersistenceController，它使用模型名称 JobLinkModel 初始化 NSPersistentContainer。 当我尝试使用以下方法保存新的 AppleUser 对象时： 让用户 = AppleUser（上下文：viewContext） user.id = UUID（） user.name = “用户 1” user.email = “...” user.password = “密码 1” user.createdAt = Date（）【电子邮件格式正确，但已替换为“...”出于隐私原因】 尝试？viewContext.save（） 我在控制台中收到以下错误：核心数据保存失败：Foundation._GenericObjCError.nilError， [：] 用户快照： [“id”： ...， “name”： “User1”， “email”： “...”， “password”： “...”， “createdAt”： ...] 所有字段都有有效值，核心数据模型似乎正确。我还尝试过： • 检查 NSPersistentContainer（name：） 中的模型名称是否与 .xcdatamodeld 文件 （JobLinkModel） 匹配 • 确保正确设置 AppleUser 实体类、模块和 Codegen（类定义、当前产品模块） • 删除重复或旧的 AppleUser 类文件 • 清理 Xcode 构建文件夹并从模拟器中删除应用程序 • 对上下文使用 @Environment（.managedObjectContext） 尽管如此，在保存新的 AppleUser 对象时，我仍然会收到 _GenericObjCError.nilError。 我想了解： 为什么即使所有字段都不是零且正确分配，核心数据也无法保存？ 这可能是由于一些残留的旧类文件引起的，还是我缺少设置中的其他内容？ 我应该采取哪些步骤来确保 Core Data 正确识别 AppleUser 实体并允许保存？ 任何帮助或指导将不胜感激。

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.