Well I think I've fixed this while waiting for Ancestry to get back to me. In the SyncReport zip file that Sync Error Reporter generates, there is a text file with a name ending _errRpt. I opened the file and used Control F to search for the word error. I found a .jpg file which had UploadError following the file name.
I then went to my tree in FTM2012 and unlinked that file telling it to move the file to the Recycle Bin. Synced and it synced ok, then added a different media file, synced again, and again all OK.
Once I've uploaded a few new media files, I'll go back and try the failing one again. Just thought I'd come back and post here in case anyone else has the same issue.
I then went to my tree in FTM2012 and unlinked that file telling it to move the file to the Recycle Bin. Synced and it synced ok, then added a different media file, synced again, and again all OK.
Once I've uploaded a few new media files, I'll go back and try the failing one again. Just thought I'd come back and post here in case anyone else has the same issue.