I'm having the same problems. I've tried downloading my tree from ancestry that worked until I made a few changes then it won't sync (same error as you). so I unlinked and uploaded my tree, which took forever, it uploaded and linked fine. Then I made some changes, and it synced. It synced a total of 4 times, then this same error while analyzing changes from family tree maker pops up. I don't know what to try next.