I get the same thing. The way I've been fixing it is going into the sqllite database (I use DB Browser for SQLLite) then into the deleted_items table. Filtering the list using the .md filename and then manually deleting the rows (with DB Browser you do have to hit the "Write Changes" button for commit). I'm syncing with DriveHQ, and using both Windows and Android. I have a sneaking suspicion it is deleting an item in Android that is triggering the issue, but that's just because I did that this morning and today was the first time I checked the sync on my windows machine and it bombed. I had deleted the welcome files from Joplin that come with the mobile app.