I have double checked my models against the incoming JSON and it all matches up properly. I inserted the recommended code above and it indeed crashes on the modelContext.save but it never gets to the catch. It simply display a SIGABRT stating "An abort signal terminated the process. Such crashes often happen because of an uncaught exception or unrecoverable error or calling the abort() function." Executing the exact same code works perfectly in iOS 18 without any changes. Calling the same endpoint and using the same JSON returned by that endpoint works without a hitch. It seems to me that if the code works in iOS 18 and fails in iOS 26, that seems to be indicative of a change in the framework that I cannot check, no?

I recovered the old project and was able to install it but any new projects cannot be installed On any of my devices.

I have additional information on this issue. When I look at the raw JSON data as received from the API call, all of the data is present, but when I look at the data after I decode it, several fields have empty strings which did have string data in the original response. In particular, display_name, list_name and list_name_encoded all have empty strings. Why would the decoding fail on simple strings and set the value to the default ""? I have uploaded JSONData.json and RawData.JSON to the above GitHub project show the differences.

Here is a GitHub link with a minimalist project that exhibits the crash after startup. https://github.com/frios/BestSellerList I have commented out the startup code under .modelContainer but the same thing happens in the ContentView.task code, just takes a few seconds longer.

Same issue here. And I have also been getting error when trying to upload appropriately sized images.

Experiencing the same issue as well.

Same happening here.