Just ignore it. The 11 users of your database have some incorrect data and it's not necessary to synch them. just go to Dashboard > Forums > Settings > Features Tab and set "Yes" the "Turn Off User Syncing Note" option.
@martin hey martin i have done that and thats fine, but now for some reason i can not change forum order it wont save and also new posts are not being added, ther is no errors on server and nothing has been changed over night