Try doing a file check first.
If you've done any client editing, try reverting those files back to a backup-ed version. If you don't have one, try getting someone to upload it for you.
Also, try making sure the fonts "Arial Black" and "MS UI Gothic" are installed and working properly since I believe that's what Lunia uses.
Did you do anything before this that may have caused it to happen? Or did it just appear?