The last couple of times I've tried syncing my online tree to my FTM I get an error and it doesn't update. The Error message reads:

An error occured while synchronizing this tree. You may want to restart FTM and try again later. but if this message recurs, you may need to unlink your trees and either upload a new linked tree from FTM or download a new linked tree from Ancestry.

How do I go about doing that so I don't lose any data or get duplicates. I'm afraid if i unlink my trees I can't download it again.

Any ideas would be awesome!