I'm getting the same exact error and it is always occurring at the same spot, for me its 80%. I am checking the logs but I don't see anything. Any help? I am able to open the company files but still transactions missing and i think its due to the fact that it just stopped at 80% and didn't finish. I know that even if it completes, your not going to get an identical match from QBO to QBD but the migration is just not completing all the way.