Hi, I am implementing a premium feature in my app where CloudKit syncing is available only for "Pro" users. The Workflow: Free Users: I initialize the ModelContainer with cloudKitDatabase: .none so their data stays local. Pro Upgrade: When a user purchases a subscription, I restart the container with cloudKitDatabase: .automatic to enable syncing. The Problem: If a user starts as "Free" (creates local data) and later upgrades to "Pro", the app crashes immediately upon launch with the following error: Fatal error: Failed to create ModelContainer: SwiftDataError(_error: SwiftData.SwiftDataError._Error.loadIssueModelContainer, _explanation: nil) It seems that SwiftData fails to load the existing data once the configuration changes to expect a CloudKit-backed store. My Question: Is there a supported way to "toggle" CloudKit on for an existing local dataset without causing this crash? I want the user's existing local data to start syncing once they pay, but currently, it just crashes. My code: import Foundation import SwiftData public enum DataModelEnum: String { case task, calendar public static let container: ModelContainer = { let isSyncEnabled = UserDefaults.isProUser let config = ModelConfiguration( groupContainer: .identifier("group.com.yourcompany.myApp"), cloudKitDatabase: isSyncEnabled ? .automatic : .none ) do { return try ModelContainer(for: TaskModel.self, CalendarModel.self, configurations: config) } catch { fatalError("Failed to create ModelContainer: \(error)") } }() }

anyone getting the following error with CloudKit+CoreData on iOS16 RC? delete/resintall app, delete user CloudKit data and reset of environment don't fix. [error] error: CoreData+CloudKit: -[NSCloudKitMirroringDelegate _requestAbortedNotInitialized:](2044): <NSCloudKitMirroringDelegate: 0x2816f89a0> - Never successfully initialized and cannot execute request '<NSCloudKitMirroringImportRequest: 0x283abfa00> 41E6B8D6-08C7-4C73-A718-71291DFA67E4' due to error: Error Domain=NSCocoaErrorDomain Code=4864 "*** -[NSKeyedUnarchiver _initForReadingFromData:error:throwLegacyExceptions:]: incomprehensible archive (0x53, 0x6f, 0x6d, 0x65, 0x20, 0x65, 0x78, 0x61)" UserInfo={NSDebugDescription=*** -[NSKeyedUnarchiver _initForReadingFromData:error:throwLegacyExceptions:]: incomprehensible archive (0x53, 0x6f, 0x6d, 0x65, 0x20, 0x65, 0x78, 0x61)}

Experiencing a crash that is only reproducible on TestFlight or AppStore version of the app, note this does not happen when running from Xcode. I've isolated the problem to sort argument being added to @Query that fetches a model that sorts based on inherited property. To reproduce: @Model class SuperModel { var createdAt: Date = .now } @available(macOS 26.0, *) @Model class SubModel: SuperModel { } @Query(sort: \SubModel.createdAt, animation: .default) private var models: [SubModel]

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?

What have people's experience with converting locally stored app data to a more browser based accessible format? Firebase seems expensive, Subabase a bit more challenging, and CloudKit too restrictive.

Hello, SwiftData is not working correctly with Swift Concurrency. And it’s sad after all this time. I personally found a regression. The attached code works perfectly fine on iOS 17.5 but doesn’t work correctly on iOS 18 or iOS 18.1. A model can be updated from the background (Task, Task.detached or ModelActor) and refreshes the UI, but as soon as the same item is updated from the View (fetched via a Query), the next background updates are not reflected anymore in the UI, the UI is not refreshed, the updates are not merged into the main. How to reproduce: Launch the app Tap the plus button in the navigation bar to create a new item Tap on the “Update from Task”, “Update from Detached Task”, “Update from ModelActor” many times Notice the time is updated Tap on the “Update from View” (once or many times) Notice the time is updated Tap again on “Update from Task”, “Update from Detached Task”, “Update from ModelActor” many times Notice that the time is not update anymore Am I doing something wrong? Or is this a bug in iOS 18/18.1? Many other posts talk about issues where updates from background thread are not merged into the main thread. I don’t know if they all are related but it would be nice to have 1/ bug fixed, meaning that if I update an item from a background, it’s reflected in the UI, and 2/ proper documentation on how to use SwiftData with Swift Concurrency (ModelActor). I don’t know if what I’m doing in my buttons is correct or not. Thanks, Axel import SwiftData import SwiftUI @main struct FB_SwiftData_BackgroundApp: App { var body: some Scene { WindowGroup { ContentView() .modelContainer(for: Item.self) } } } struct ContentView: View { @Environment(\.modelContext) private var modelContext @State private var simpleModelActor: SimpleModelActor! @Query private var items: [Item] var body: some View { NavigationView { VStack { if let firstItem: Item = items.first { Text(firstItem.timestamp, format: Date.FormatStyle(date: .omitted, time: .standard)) .font(.largeTitle) .fontWeight(.heavy) Button("Update from Task") { let modelContainer: ModelContainer = modelContext.container let itemID: Item.ID = firstItem.persistentModelID Task { let context: ModelContext = ModelContext(modelContainer) guard let itemInContext: Item = context.model(for: itemID) as? Item else { return } itemInContext.timestamp = Date.now.addingTimeInterval(.random(in: 0...2000)) try context.save() } } .buttonStyle(.bordered) Button("Update from Detached Task") { let container: ModelContainer = modelContext.container let itemID: Item.ID = firstItem.persistentModelID Task.detached { let context: ModelContext = ModelContext(container) guard let itemInContext: Item = context.model(for: itemID) as? Item else { return } itemInContext.timestamp = Date.now.addingTimeInterval(.random(in: 0...2000)) try context.save() } } .buttonStyle(.bordered) Button("Update from ModelActor") { let container: ModelContainer = modelContext.container let persistentModelID: Item.ID = firstItem.persistentModelID Task.detached { let actor: SimpleModelActor = SimpleModelActor(modelContainer: container) await actor.updateItem(identifier: persistentModelID) } } .buttonStyle(.bordered) Button("Update from ModelActor in State") { let container: ModelContainer = modelContext.container let persistentModelID: Item.ID = firstItem.persistentModelID Task.detached { let actor: SimpleModelActor = SimpleModelActor(modelContainer: container) await MainActor.run { simpleModelActor = actor } await actor.updateItem(identifier: persistentModelID) } } .buttonStyle(.bordered) Divider() .padding(.vertical) Button("Update from View") { firstItem.timestamp = Date.now.addingTimeInterval(.random(in: 0...2000)) } .buttonStyle(.bordered) } else { ContentUnavailableView( "No Data", systemImage: "slash.circle", // 􀕧 description: Text("Tap the plus button in the toolbar") ) } } .toolbar { ToolbarItem(placement: .primaryAction) { Button(action: addItem) { Label("Add Item", systemImage: "plus") } } } } } private func addItem() { modelContext.insert(Item(timestamp: Date.now)) try? modelContext.save() } } @ModelActor final actor SimpleModelActor { var context: String = "" func updateItem(identifier: Item.ID) { guard let item = self[identifier, as: Item.self] else { return } item.timestamp = Date.now.addingTimeInterval(.random(in: 0...2000)) try! modelContext.save() } } @Model final class Item: Identifiable { var timestamp: Date init(timestamp: Date) { self.timestamp = timestamp } }

I have an iOS app (1Address) which allows users to share their address with family and friends using CloudKit Sharing. Users share their address record (CKRecord) via a share link/url which when tapped allows the receiving user to accept the share and have a persistent view into the sharing user's address record (CKShare). However, most users when they recieve a sharing link do not have the app installed yet, and so when a new receiving user taps the share link, it prompts them to download the app from the app store. After the new user downloads the app from the app store and opens the app, my understanding is that the system (iOS) will/should then vend to my app the previously tapped cloudKitShareMetadata (or share url), however, this metadata is not being vended by the system. This forces the user to re-tap the share link and leads to some users thinking the app doesn't work or not completing the sharing / onboarding flow. Is there a workaround or solve for this that doesn't require the user to tap the share link a second time? In my scene delegate I am implementing: func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {...} And also func scene(_ scene: UIScene, continue userActivity: NSUserActivity) {...} And also: func windowScene(_ windowScene: UIWindowScene, userDidAcceptCloudKitShareWith cloudKitShareMetadata: CKShare.Metadata) {...} And: func scene(_ scene: UIScene, openURLContexts URLContexts: Set<UIOpenURLContext>) {...} Unfortunately, none of these are called or passed metadata on the initial app run after install. Only after the user goes back and taps a link again can they accept the share. This documentation: https://aninterestingwebsite.com/documentation/cloudkit/ckshare says that adding the CKSharingSupported key to your app's Info.plist file allows the system to launch your app when a user taps or clicks a share URL, but it does not clarify what should happen if your app is being installed for the first time. This seems to imply that the system is holding onto the share metadata and/or url, but for some reason it is not being vended to the app on first run. Open to any ideas here for how to fix and I also filed feedback: FB20934189.

I'm building a macOS + iOS SwiftUI app using Xcode 14.1b3 on a Mac running macOS 13.b11. The app uses Core Data + CloudKit. With development builds, CloudKit integration works on the Mac app and the iOS app. Existing records are fetched from iCloud, and new records are uploaded to iCloud. Everybody's happy. With TestFlight builds, the iOS app has no problems. But CloudKit integration isn't working in the Mac app at all. No existing records are fetched, no new records are uploaded. In the Console, I see this message: error: CoreData+CloudKit: Failed to set up CloudKit integration for store: <NSSQLCore: 0x1324079e0> (URL: <local file url>) Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service named com.apple.cloudd was invalidated: failed at lookup with error 159 - Sandbox restriction." UserInfo={NSDebugDescription=The connection to service named com.apple.cloudd was invalidated: failed at lookup with error 159 - Sandbox restriction.} I thought it might be that I was missing the com.apple.security.network.client entitlement, but adding that didn't help. Any suggestions what I might be missing? (It's my first sandboxed Mac app, so it might be really obvious to anyone but me.)

I'm using SwiftData with CloutKit with a very simple app. Data syncs between iOS, iPadOS, and visionOS, but not macOS. From what I can tell, macOS is never getting CK messages unless I'm running the app from Xcode. I can listen for the CK messages and show a line in a debug overlay. This works perfectly when I run from Xcode. I can see the notifications and see updates in my app. However, if I just launch the app outside of Xcode I will never see any changes or notifications. It is as if the Mac app never even tries to contact CloudKit. Schema has been deployed in the CloudKit console. The app is based on the multi-platform Xcode template. Again, only the macOS version has this issue. Is there some extra permission or setting I need to set up in order to use CloudKit on macOS? @State private var publisher = NotificationCenter.default.publisher(for: NSPersistentCloudKitContainer.eventChangedNotification).receive(on: DispatchQueue.main) .onReceive(publisher) { notification in // Listen for changes in CK events if let userInfo = notification.userInfo, let event = userInfo[NSPersistentCloudKitContainer.eventNotificationUserInfoKey] as? NSPersistentCloudKitContainer.Event { let message = "CloudKit Sync: \(event.type.rawValue) - \(event.succeeded ? "Success" : "Failed") - \(event.description)" // Store for UI display syncNotifications.append(message) if syncNotifications.count > 10 { syncNotifications.removeFirst() } } } .overlay(alignment: .topTrailing) { if !syncNotifications.isEmpty { VStack(alignment: .leading) { ForEach(syncNotifications, id: \.self) { notification in Text(notification) .padding(8) } } .frame(width: 800, height: 500) .cornerRadius(8) .background(Color.secondary.opacity(0.2)) .padding() .transition(.move(edge: .top)) } }

I have some code which handles doing some computation on a background thread before updating Core Data NSManagedObjects by using the NSManagedObjectContext.perform functions. This code is covered in Sendable warnings in Xcode 26 (beta 6) because my NSManagedObject subclasses (autogenerated) are non-Sendable and NSManagedObjectContext.perform function takes a Sendable closure. But I can't really figure out what I should be doing. I realize this pattern is non-ideal for Swift concurrency, but it's what Core Data demands AFAIK. How do I deal with this? let moc = object.managedObjectContext! try await moc.perform { object.completed = true // Capture of 'object' with non-Sendable type 'MySpecialObject' in a '@Sendable' closure try moc.save() } Thanks in advance for your help!

Hi, I was testing the new iOS 18 behavior where NSPersistentCloudKitContainer wipes the local Core Data store if the user logs out of iCloud, for privacy purposes. I ran the tests both with a Core Data + CloudKit app, and a simple one using SwiftData with CloudKit enabled. Results were identical in either case. In my testing, most of the time, the feature worked as expected. When I disabled iCloud for my app, the data was wiped (consistent with say the Notes app, except if you disable iCloud it warns you that it'll remove those notes). When I re-enabled iCloud, the data appeared. (all done through the Settings app) However, in scenarios when NSPersistentCloudKitContainer cannot immediately sync -- say due to rate throttling -- and one disables iCloud in Settings, this wipes the local data store and ultimately results in data loss. This occurs even if the changes to the managed objects are saved (to the local store) -- it's simply they aren't synced in time. It can be a little hard to reproduce the issue, especially since when you exit to the home screen from the app, it generally triggers a sync. To avoid this, I swiped up to the screen where you can choose which apps to close, and immediately closed mine. Then, you can disable iCloud, and run the app again (with a debugger is helpful). I once saw a message with something along the lines of export failed (for my record that wasn't synced), and unfortunately it was deleted (and never synced). Perhaps before NSPersistentCloudKitContainer wipes the local store it ought to force sync with the cloud first?

I have an app that from day 1 has used Swiftdata and successfully sync'd across devices with Cloudkit. I have added models to the data in the past and deployed the schema and it continued to sync across devices. Sometime I think in June.2025 I added a new model and built out the UI to display and manage it. I pushed a version to Test Flight (twice over a matter of 2 versions and a couple of weeks) and created objects in the new model in Test Flight versions of the app which should push the info to Cloudkit to update the schema. When I go to deploy the schema though there are no changes. I confirmed in the app that Cloudkit is selected and it's point to the correct container. And when I look in Cloudkit the new model isn't listed as an indes. I've pushed deploy schema changes anyway (more than once) and now the app isn't sync-ing across devices at all (even the pre-existing models aren't sync-ing across devices). I even submitted the first updated version to the app store and it was approved and released. I created objects in the new model in production which I know doesn't create the indexes in the development environment. But this new model functions literally everywhere except Cloudkit and I don't know what else to do to trigger an update.

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

Hi everyone, I’m working on an offline-first iOS app using Core Data. I have a question about safe future updates: in my project, I want to be able to add new optional fields to existing Entities or even completely new Entities in future versions — but nothing else (no renaming, deleting, or type changes). Here’s how my current PersistenceController looks: import CoreData struct PersistenceController { static let shared = PersistenceController() let container: NSPersistentContainer init(inMemory: Bool = false) { container = NSPersistentContainer(name: "MyApp") if inMemory { container.persistentStoreDescriptions.first!.url = URL(fileURLWithPath: "/dev/null") } container.loadPersistentStores(completionHandler: { (storeDescription, error) in if let error = error as NSError? { print("Core Data failed to load store: \(error), \(error.userInfo)") } }) container.viewContext.automaticallyMergesChangesFromParent = true } } Do I need to explicitly set these properties to ensure lightweight migration works? shouldMigrateStoreAutomatically = true shouldInferMappingModelAutomatically = true Or, according to the documentation, are they already true by default, so I can safely add optional fields and new Entities in future versions without breaking users’ existing data? Thanks in advance for your guidance!

Good morning everyone! Today I have a question about using SwiftData with CloudKit and Widgets. I recently set up my project for SwiftData and CloudKit synchronization, but for some reason, I’m not able to give my Widget access to this data. CloudKit works perfectly fine for my main app, but the Widget only shows placeholder data(the placeholder data which were defined in the get functions as catch, this is sure). I have set the CloudKit capability for my Widget extension and tried fetching data with the get-functions in the code below. I also ensured that the data model files are members of the Widget extension target and that the Widget extension uses the same CloudKit container as the main app. I wondered if it is possible and reasonable to save a copy of my CloudKit data in an App Group container, but in that case, the information shown in the Widget are not always up-to-date, so a solution that fetches data directly from CloudKit would be better. Has anyone had experience with this case? I couldn’t find much information about this problem online. In the code below, many parts have been deleted or altered because they are not relevant to the problem, as they don’t fetch data. The variables, functions, and data models in the code may sometimes have German names, but I hope you can still understand it. Thanks for your help! struct Provider: AppIntentTimelineProvider { //[Placeholder and snapshot] func timeline(for configuration: ConfigurationAppIntent, in context: Context) async -> Timeline<CleverEntry> { let entry = await loadAllVariables() return Timeline(entries: [entry], policy: .after(Date().addingTimeInterval(60 * 5))) } @MainActor private func getExam() -> [PruefungM] { //Old, local version /* guard let modelContainer = try? ModelContainer(for: PruefungM.self) else { return [] } let descriptor = FetchDescriptor<PruefungM>() let PRF = try? modelContainer.mainContext.fetch(descriptor) return PRF ?? [] */ do { let configuration = ModelConfiguration(cloudKitDatabase: .private("iCloud.my_bundle_id")) let container = try ModelContainer( for: PruefungM.self, configurations: configuration ) let descriptor = FetchDescriptor<PruefungM>() return try container.mainContext.fetch(descriptor) } catch { print("❌ Error(CloudKit): \(error)") return [] } } @MainActor private func getHAF() -> [HausaufgabeM] { do { let configuration = ModelConfiguration(cloudKitDatabase: .private("iCloud.my_bundle_id")) let container = try ModelContainer( for: HausaufgabeM.self, configurations: configuration ) let descriptor = FetchDescriptor<HausaufgabeM>() return try container.mainContext.fetch(descriptor) } catch { print("❌ Error (CloudKit): \(error)") return [] } } @MainActor private func loadAllVariables() -> CleverEntry { print("Function started") let HAF = getHAF() let PRF = getExam() //handling and returning the data } }

Hi everyone, Im trying to set up CloudKit for my Unreal Engine 5.4 project but seem to be hitting some roadblocks on how to set up the Record Types. From my understanding I need to set up a "file" record type with a "contents" asset field - but even with this it doesn't seem to work :( Any unreal engine devs with some experience on this who could help me out? Thanks!

Hello Devs, I'm encountering a persistent INTERNAL_ERROR (HTTP 500) when making Server-to-Server API calls to CloudKit, specifically when trying to hit the /users/current endpoint, even after meticulously verifying all client-side components. I'm hoping someone might have insight into what could cause this. Context: Goal: Authenticate to CloudKit from a Vercel Serverless Function (Node.js) to perform operations like record queries. Problem Endpoint: POST https://api.apple-cloudkit.com/database/1/iCloud.com.dannybaseball.Danny-Baseball/production/public/users/current Key Generation Method: Using the CloudKit Dashboard's "Tokens &amp; Keys" -&gt; "New Server-to-Server Key" flow, where I generate the private key using openssl ecparam -name prime256v1 -genkey -noout -out mykey.pem, then extract the public key using openssl ec -in mykey.pem -pubout, and paste the public key material (between BEGIN/END markers) into the dashboard. The private key was then converted to PKCS#8 format using openssl pkcs8 -topk8 -nocrypt -in mykey.pem -out mykey_pkcs8.pem. Current Setup Being Tested (in a Vercel Node.js function): CLOUDKIT_CONTAINER: iCloud.com.dannybaseball.Danny-Baseball CLOUDKIT_KEY_ID: 9368dddf141ce9bc0da743b9f69bc3eda132b9bb3e62a4167e428d4f320b656e (This is the Key ID generated from the CloudKit Dashboard for the public key I provided). CLOUDKIT_P8_KEY (Environment Variable): Contains the base64 encoded string of the entire content of my PKCS#8 formatted private key file. Key Processing in Code: const p8Base64 = process.env.CLOUDKIT_P8_KEY; const privateKeyPEM = Buffer.from(p8Base64, 'base64').toString('utf8'); // This privateKeyPEM string starts with "-----BEGIN PRIVATE KEY-----" and ends with "-----END PRIVATE KEY-----" const privateKey = crypto.createPrivateKey({ key: privateKeyPEM, format: 'pem' }); // This line SUCCEEDS without DECODER errors in my Vercel function logs. Use code with caution. JavaScript Request Body for /users/current: "{}" Signing String (message = Date:BodyHash:Path): Date: Correct ISO8601 format (e.g., "2025-05-21T19:38:11.886Z") BodyHash: Correct SHA256 hash of "{}", then Base64 encoded (e.g., "RBNvo1WzZ4oRRq0W9+hknpT7T8If536DEMBg9hyq/4o=") Path: Exactly /database/1/iCloud.com.dannybaseball.Danny-Baseball/production/public/users/current Headers: X-Apple-CloudKit-Request-KeyID: Set to the correct Key ID. X-Apple-CloudKit-Request-ISO8601Date: Set to the date used in the signature. X-Apple-CloudKit-Request-SignatureV1: Set to the generated signature. X-Apple-CloudKit-Environment: "production" Content-Type: "application/json" Observed Behavior &amp; Logs: The Node.js crypto.createPrivateKey call successfully parses the decoded PEM key in my Vercel function. The request is sent to CloudKit. CloudKit responds with HTTP 500 and the following JSON body (UUID varies per request): { "uuid": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", "serverErrorCode": "INTERNAL_ERROR" } Use code with caution. Json This happens consistently. Previously, with other key pairs or different P8 processing attempts, I was getting AUTHENTICATION_FAILED (401) or local DECODER errors. Now that the key parsing is successful on my end with this current key pair and setup, I'm hitting this INTERNAL_ERROR. Troubleshooting Done: Verified Key ID (9368dddf...) is correct and corresponds to the key generated via CloudKit Dashboard. Verified Container ID (iCloud.com.dannybaseball.Danny-Baseball) is correct. Successfully parsed the private key from the environment variable (after base64 decoding) within the Vercel function. Meticulously checked the signing string components (Date, BodyHash, Path) against Apple's documentation. Path format is /database/1////. Ensured all required headers are present with correct values. Local Node.js tests (bypassing Vercel but using the same key data and signing logic) also result in this INTERNAL_ERROR. Question: What could cause CloudKit to return an INTERNAL_ERROR (500) for a /users/current request when the client-side key parsing is successful and all request components (path, body hash for signature, date, headers) appear to conform exactly to the Server-to-Server Web Services Reference? Are there any known subtle issues with EC keys generated via openssl ecparam (and then converted to PKCS#8) that might lead to this, even if crypto.createPrivateKey parses them in Node.js? Could there be an issue with my specific Key ID or container that would manifest this way, requiring Apple intervention? Any insights or suggestions would be greatly appreciated. I can provide more detailed logs of the request components if needed. Thank you!

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.

I am working on a SwiftUI project using Core Data. I have an entity called AppleUser in my data model, with the following attributes: id (UUID), name (String), email (String), password (String), and createdAt (Date). All attributes are non-optional. I created the corresponding Core Data class files (AppleUser+CoreDataClass.swift and AppleUser+CoreDataProperties.swift) using Xcode’s automatic generation. I also have a PersistenceController that initializes the NSPersistentContainer with the model name JobLinkModel. When I try to save a new AppleUser object using: let user = AppleUser(context: viewContext) user.id = UUID() user.name = "User1" user.email = "..." user.password = "password1" user.createdAt = Date()【The email is correctly formatted, but it has been replaced with “…” for privacy reasons】 try? viewContext.save() I get the following error in the console:Core Data save failed: Foundation._GenericObjCError.nilError, [:] User snapshot: ["id": ..., "name": "User1", "email": "...", "password": "...", "createdAt": ...] All fields have valid values, and the Core Data model seems correct. I have also tried: • Checking that the model name in NSPersistentContainer(name:) matches the .xcdatamodeld file (JobLinkModel) • Ensuring the AppleUser entity Class, Module, and Codegen are correctly set (Class Definition, Current Product Module) • Deleting duplicate or old AppleUser class files • Cleaning Xcode build folder and deleting the app from the simulator • Using @Environment(.managedObjectContext) for the context Despite all this, I still get _GenericObjCError.nilError when saving a new AppleUser object. I want to understand: 1. Why is Core Data failing to save even though all fields are non-nil and correctly assigned? 2. Could this be caused by some residual old class files, or is there something else in the setup that I am missing? 3. What steps should I take to ensure that Core Data properly recognizes the AppleUser entity and allows saving? Any help or guidance would be greatly appreciated.