run file verification tool from tools & maintenance section to find changed & missing files
Did you followed the ACP Pin tutorial by Paul H. ?
I don't believe my tutorial would cause this...
Could you post your URL and a admin account username and password in the
Private Inquiries forum?
No Paul, it won't cause certainly because I myself use that.
I was asking because in case if he did some wrong edits in class_form.php , then it might.
Upload your admin folder again, you must be missing something here.