@Barb...I emailed ancestry about this error back in December and got the same answer from ancestry that you did. After several attempts to do what they suggested, even one attempt that merged date and media from another tree I have, I finally got it to successfully. Then, a few days ago, this same problem happened again and I still cannot sync.
I am seriously tired of dealing with ancestry regarding several issues over several years. I've emailed and called and even had a person from ancestry agree that there were issues that haven't been worked on or been solved. So, I will not contact them again. They have my previous submissions they can look at.
Thank you, though, for asking for emails to be sent. Hopefully, those who haven't sent emails will do so.
An equally frustrated person!