Quinn, We're hitting this very occasionally, and it seems that our document class is sometimes being dealloced on a background thread: 10 Foundation 0x00007fff3c06252c -[_NSXPCConnectionExportedObjectTable releaseExportedObject:] + 297 At first I thought it might be an artefact of running in Xcode, because we weren't seeing it in bug reports. But now I've seen it from a user, too. Any thoughts on how to handle this?

Thanks as always, Quinn. I'd been assuming the -[_NSXPCConnectionExportedObjectTable releaseExportedObject:] implied it was the OS's doing, but perhaps that's too simplistic a reading of things.