I just responded to your ticket, if you haven't seen it:
Can you confirm that you have a data/ and internal_data/ directory in your XenForo directory? If so, what contents are within them?
If they appear to be empty (or are not there), you may have lost attachments and avatars that were stored within. I would recommend restoring your files from a backup and then reupload the files for 1.2, ensuring that the merging approach is used.