Added a @try block to catch exceptions thrown when applying sync change sets. This is possible, for example, if an object object is deleted, and a 'could not fulfill fault' exception arises. (by @drewmccormack)
Reworked the ubiquity monitor again. It was stalling the main queue for too long. Now move the download initiations to the background, and it seems to work better. (by @drewmccormack)
Changed the timeout before a file gets migrated out of iCloud and back in again to 12 hours. Also improved the predicate used to for metadata query to download new cloud files. (by @drewmccormack)