Upload this little script on your main MyBB folder and run it once by opening the file on your browser (eg.: if your site is http://example.org, then open http://example.org/myfbrestore.php).
It will check for missing columns and it will restore them if not found. Then you should uninstall MyFacebook Connect and reinstall it.
It will check for missing columns and it will restore them if not found. Then you should uninstall MyFacebook Connect and reinstall it.