[accessdeniedzzz]

any one can help how to fix this error ?:

Database error in vBulletin 3.6.4:

Invalid SQL:
SELECT `username` FROM `user` WHERE `usergroupid` IN ();

MySQL Error : You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')' at line 1
Error Number : 1064
Date : Sunday, May 6th 2007 @ 04:15:01 PM
Script : http://www.MYSITE.com/private.php?do=insertpm&pmid=
Referrer : https://www.MYSITE.com/private.php?do=newpm&u=1
IP Address : XXXXXX
Username : admin
Classname : vB_Database