I always had problems with NSFetchedResultsController and dynamic cell updates. I never was able to fix it, some really strange bugs were in there. I used to write some workarounds (like the crash when you tell UITableView to update a certain cell more than once… but in the end i always worked on the symptoms, not the cause.

Then i found THIS.

Somebody wrote a wrapper for NSFetchedResultsController called SafeFetchedResultsController, that fixes bugs that are there since it’s first release (tested on iOS 4.1). Apple has to be aware of this, but maybe they don’t fix it because it must certainly would break existing applications.

This wrapper is a direct replacement, it subclasses Apple’s class, carefully analyzes the update messages and fixes them if they are wrong. And guess what… it works! It’s so great to finally fix this issue and enable smooth animations instead of the brutal (but working) [tableView reloadData].

So if your app is crashing randomly with messages like “Exception was caught during Core Data change processing”, this one is for you.

Related posts:

1. on fixing symbolicatecrash