NSPersistentCloudKitContainer

One root cause that we have identified for this issue is removing a many-to-many relationship from your model. This is supposed to be a supported migration, so we are collecting feedback reports to track against that as a bug. If you would like to be notified of a fix for that share your feedback number here and we can relate them together. As a workaround you can simply add the relationship back. Or, attempt a more detailed / invasive solution described below. Our schema is public and described here: https://developer.apple.com/documentation/coredata/mirroring_a_core_data_store_with_cloudkit/reading_cloudkit_records_for_core_data Your container will contain CDMR records that identify the offending relationship. The fields CD_entityNames and CD_relationships can be used to tell which relationship a record represents. One (or more, depending on how many relationships you removed) of those records may be causing this issue. You can choose to: Add the missing relationship back to your model Delete the offending

It's hard to tell if Apple uses Core Data and CloudKit, but my guess is that they do. I'm not really sure what you mean by reordering items but I can tell you that using Core Data and CloudKit is very straightforward, just search for NSPersistentCloudKitContainer for using CloudKit and for Core Data I highly recommend you to watch the following tutorials; they're great. Swiftful Thinking: https://www.youtube.com/watch?v=BPQkpxtgalY

I get the error This NSPersistentStoreCoordinator has no persistent stores (unknown). It cannot perform a save operation. What does this error exactly mean? The error message says the persistent store coordinator has no persistent stores. Core Data saves data to a persistent store. If there are no persistent stores, Core Data cannot save your app's data. My container is initialised so it should have a persistent store, right? Are you sure the container was initialized correctly? let container = NSPersistentCloudKitContainer(name: TaskDataModel) Do you have a CloudKit container named TaskDataModel? Set a breakpoint at the start of the init function in DataController. Does the container property have the value you expect? Step through the code line by line. Does the call to loadPersistentStores run correctly or does it generate an error?

Yes. the current design of NSPersistentCloudKitContainer is to sync everything. There are other sync engines available between CoreData and CloudKit, such as CKSyncEngine in iOS 17, and open source sun engines like CloudCore, which might provide more fine-grain control over sync. And of course, you can always write your own that best suits your needs.

@CrunchyBagel Thank you! That is also helpful. I wasn't aware that initializeCloudKitSchema() was different than just manually promoting from development to production after creating test records within the App but I see what you mean now. I thought that NSPersistentCloudKitContainer created all necessary records in the development environment based on whatever is defined inxcdatamodeld as part of how it works and you then later promote those to production. I see it only creates records based on the specific data that has been uploaded which isn't going to include optional _ckAsset records and other things unless those were specifically needed for the test data. Again, much appreciated!