I'm having the same issue with an established app with Xcode 12 & iOS14 using NSPersistentCloudKitContainer. When I try to run the exact code with iOS15 & Xcode 13 (Developer Beta 1 for both) I see the "Failed to sync user keys" error. I suspect this is an early beta bug so hopefully it will disappear in subsequent betas.

Hopefully we'll find out next week when beta 2 drops! 🤞🏼😬

Seems like a new issue in Beta 4 resulting in this error: "Account Temporarily Unavailable" (1028/2011); "Account temporarily unavailable due to bad or missing auth token" 'Reset All Contents & Settings' on the simulator doesn't appear to fix it this time. I've also noticed that the current App Store release version of my App which uses NSPersistentCloudKitContainer does not sync properly and crashes after 30 seconds. Nothing has changed other than installing Beta 4. I've submitted a bug report to Apple.

This is NOT fixed with beta 5. Two problems related to NSPersistentCloudkitContainer persist since beta 4. I've submitted a bug report to Apple - no response yet. The issues: "Account temporarily unavailable due to bad or missing auth token" when using the Development Environment (device or simulator), despite being signed in and despite it working on beta 1, 2 & 3. When using the App Store version of my App (in the Production Environment) on an iOS 15 device (beta 4 & 5), the syncing appears to start but nothing syncs. The app crashes to the springboard after a minute without warning. Crash reports are vague but I have captured a CloudKit sysdiagnose and sent it to Apple in the hope they can decipher it. I really hope they sort this out as it's going to render my currently available app useless if iOS15 is released in this state and my users install it.

OK, commenting on your thread as I have the same issue (which you've found). Let's hope Apple is able to track down what's going on here. Only started with iOS15 beta 4 from my testing. https://developer.apple.com/forums/thread/687877

This seemed to coincide with other changes to NSPersistenCloudkitContainer's console outputs when syncing since beta 4. Something big has been changed behind the scenes I think and it's very much 'beta' again.

Here is a screenshot of the call tree from Instruments and what's chewing up the RAM. There is something broken with the NSCloudKitMirroringDelegate since iOS15 beta 4 (and still not working in beta 6).

That call tree image is practically identical to mine. In a way I'm relieved as it's unlikely to be my fault! 😅

I bought a new iPad and using my app (downloaded from the App Store, not via Xcode) I can confirm that: Data created/modified on iOS 14.7.1 successfully syncs bidirectionally on iOS 14.7.1 devices Data created/modified on iOS 14.7.1 successfully syncs down only to iOS 15 (beta 4, 5 or 6) devices Data created/modified on iOS 15 (beta 4, 5 or 6) does not upload to iCloud (and eventually crashes the App)^ In order to see the iOS 14.7.1 -> iOS 15 (beta) changes appear I have to reload the app as the download seems to occur before the upload. Once the upload task 'starts' (it never really actually uploads anything), it prevents any changes from downloading. I've made no changes to my code, data model or NSPersistentCloudkitContainer related methods and it was something that abruptly appeared after installing iOS 15 beta 4. ^ basically any changes made on the device after iOS 15 (beta 4) was installed have not ever been sent to iCloud.

This won’t answer your question, sorry… but it might be related to the problem several of us are having with NSPersistentCloudKitContainer - it seemed to appear with beta 4 and is still present with beta 7. Something fundamental was modified in beta 4 and sure hope it’s fixed before release otherwise I’m in real trouble (from my users!). See here for my thread on the issue.

Found this potentially related thread: https://developer.apple.com/forums/thread/688792?page=1#686082022 I’ve not hit these errors with the macOS version (not tried it), but it looks like it’s the same issue with NSCloudKitMirroringDelegate gobbling up available resources and crashing.

Have you received any update from Apple on this? They have not replied to my Feedback report at all - not even acknowledged the receipt of my test data, or if it might even be something I’ve done wrong. Nothing. We’re about a month away from release and this is going to break my app if not fixed - which has been working fine for the past 2 years using NSPersistentCloudKitContainer. I suspect there will be a lot of developers & users that will be caught off-guard if it’s released to the public as it’s only a ‘visible’ problem for those of us with slightly complex Core Data models. My app is a medical record keeping app and my users are going to be extremely angry when it fails to sync after they upgrade to iOS15 if this isn’t fixed. In my line of work (I’m an MD) this poor (or no) communication would see me sued by my patients (and quite rightly too) - people just need to know something is being done. Something fundamentally changed with NSPersistentCloudKitContainer from beta 4 and this was obvious when you looked at the formatting of the console output when a sync did occur. It was totally different suddenly - it was the first thing I noticed. The second thing I noticed was that it didn’t work… This is the first time, since I returned to Apple in 2004, that I feel really disappointed in them. Sigh.

Just installed the RC versions of iOS 15 & Xcode 13 and it's still broken. After ingesting external data into my Core Data store & saving the context, I get messages in the console that suggests something will happen... then the memory & CPU use keeps climbing until it crashes. I've tried Resetting the Development Environment Erasing & Resetting the Simulator At the end of my data import (from an external backup file), which saves to Core Data just fine, the console shows this: CoreData: CloudKit: CoreData+CloudKit: -[PFCloudKitExportContext processAnalyzedHistoryInStore:inManagedObjectContext:error:]_block_invoke_3(251): Finished processing analyzed history with 30421 metadata objects to create, 0 deleted rows without metadata. 2021-09-15 07:27:25.213430+1000 Somnus[37796:7522408] [BackgroundTask] Background Task 99 ("CoreData: CloudKit Export"), was created over 30 seconds ago. In applications running in the background, this creates a risk of termination. Remember to call UIApplication.endBackgroundTask(_:) for your task in a timely manner to avoid this. No syncing occurs and all that happens is CPU & Memory consumption goes through the roof as it has done since iOS 15 beta 4. Everything you see here is 100% NSCloudKitMirroringDelegate - it's insane, especially considering the data that needs to sync is only about 500MB. No code of mine is running at all - the App is just idling!! This is totally unacceptable for a RC version and it's breaking my existing App Store application so when my users upgrade from iOS 14 -> 15 it's going to stop syncing (and god knows how out-of-sync it's going to get). My App is in use by medical professionals and they're not going to be very happy with me. I so disappointed with this I've effectively stopped prepping the next update of my app. This is just awful.

Not an answer I’m afraid, but perhaps a related problem. They’ve definitely changed something deep at the OS level which is even affecting the CloudKit syncing of apps built with the iOS 14 SDK many months ago (ie. my app!) if run on an iOS 15 device, let alone apps built with the iOS 15 SDK! This failure of syncing started to occur when iOS 15 beta 4 was released - prior to this it was all working normally, as it did in iOS 13 & iOS 14. From beta 4 the entire structure of the console log outputs for NSPersistentCloudKitContainer changed, so something fundamental changed with CloudKit at this time. In my case, it seems it has trouble syncing Core Data relationships and NSPersistentCloudKitMirrorringDelegate gets stuck in a loop causing CPU & RAM consumption to rise uncontrollably, with the OS killing the app shortly afterwards. No syncing occurs. My Core Data structure has not changed since iOS 14 and my app synced (and still does) just fine on iOS 14 devices. Other than a reply from a ‘Frameworks Engineer’ briefly, I’ve had no communication from Apple, nor an acknowledgement that this is even an issue, including in my Feedback report - nobody from Apple has replied there. It’s extremely disheartening particularly as they’ve released the Release Candidate and it’s still broken. I’m going to have many very upset users (medical professionals) in a few days. If it didn’t affect Apps built 6 months ago with the iOS 14 SDK I wouldn’t really be that concerned as I could just hold off my iOS 15 release until this is fixed, but it’s breaking existing apps which is totally unacceptable. Here’s my thread on it: https://developer.apple.com/forums/thread/687877 I’ve submitted a Technical Support Incident (at my expense) now that iOS 15 is ‘final’ in the hope that someone will acknowledge this!

Sorry, Apple... this is still broken in iOS 15.1 (beta 2) The CPU & RAM usage is still excessive and no syncing occurs at all. I've replied to my TSI in the hope I can get someone to look into this as a matter of urgency. I now have users running iOS 15 who are no longer seeing their data syncing via iCloud, resulting in a terrible user experience, using my app downloaded from the App Store which has been unchanged since iOS 14. Whatever Apple did in iOS 15 beta 4 to NSPersistentCloudKitContainer, they broke it badly. Maybe users who don't have complex databases aren't seeing this problem, but the whole point of NSPersistentCloudKitContainer is to sync a Core Data store with complex relationships (and besides, it works just fine on iOS 13 & iOS 14!). My testing setup Monterey (beta 8) Xcode 13 (13A233) non-beta Testing on iPhone 13 Pro with iOS 15.1 (beta 2) Preparation Deleted iCloud data for my app Deleted my app from the device (App Store download) Rebooted device Reset the iCloud Container Development Environment Built & run my app using Xcode on my iPhone 13 Pro Results I ingested an external backup file into my app, which saved to Core Data perfectly without any errors. This backup file restores the user database which contains lots of many-to-many and one-to-many relationships (the entire POINT of using Core Data). After the import and the context was saved, the console shows this: CoreData: debug: CoreData+CloudKit: -[NSCloudKitMirroringDelegate managedObjectContextSaved:](2530): <NSCloudKitMirroringDelegate: 0x2806a4dd0>: Observed context save: <NSPersistentStoreCoordinator: 0x2816b0070> - <NSManagedObjectContext: 0x2806ac1a0> CoreData: debug: CoreData+CloudKit: -[NSCloudKitMirroringDelegate managedObjectContextSaved:](2530): <NSCloudKitMirroringDelegate: 0x2806a4dd0>: Observed context save: <NSPersistentStoreCoordinator: 0x2816b0070> - <NSManagedObjectContext: 0x2806ac1a0> CoreData: debug: CoreData+CloudKit: -[NSCloudKitMirroringDelegate managedObjectContextSaved:](2530): <NSCloudKitMirroringDelegate: 0x2806a4dd0>: Observed context save: <NSPersistentStoreCoordinator: 0x2816b0070> - <NSManagedObjectContext: 0x2806ac1a0> CoreData: debug: CoreData+CloudKit: -[NSCloudKitMirroringDelegate managedObjectContextSaved:](2530): <NSCloudKitMirroringDelegate: 0x2806a4dd0>: Observed context save: <NSPersistentStoreCoordinator: 0x2816b0070> - <NSManagedObjectContext: 0x2806ac1a0> CoreData: debug: CoreData+CloudKit: -[NSCloudKitMirroringDelegate managedObjectContextSaved:](2530): <NSCloudKitMirroringDelegate: 0x2806a4dd0>: Observed context save: <NSPersistentStoreCoordinator: 0x2816b0070> - <NSManagedObjectContext: 0x2806ac1a0> CoreData: CloudKit: CoreData+CloudKit: -[PFCloudKitExportContext processAnalyzedHistoryInStore:inManagedObjectContext:error:]_block_invoke_3(251): Finished processing analyzed history with 19785 metadata objects to create, 0 deleted rows without metadata. Then the CPU & Memory usage starts to rise as before, although not as dramatically, so it takes longer to crash, giving the impression that this is 'fixed', yet absolutely no data is being transmitted from the device - zero syncing is occurring. After several minutes of no activity (other than rising RAM consumption) iOS kills the app for 'using too much memory' - awesome... What Now? So the question is what on earth do I do now? It's been months for this to be acknowledged and now we're being told it's 'fixed' when it's just as broken. What was changed in iOS 15 beta 4 that totally wrecked this... months ago? If this won't be fixed then I have no choice but to abandon my apps and stop development. I really hope this isn't how it's going to end...