When i try to remove the product i get this error.

Database error in vBulletin 3.8.7:

Invalid SQL:
UPDATE user SET usergroupid = 2 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
Request Date : Thursday, September 29th 2011 @ 01:11:58 PM
Error Date : Thursday, September 29th 2011 @ 01:11:58 PM
Script : Log in - Computer Juice - vBulletin Admin Control Panel
Referrer : Log in - Computer Juice - vBulletin Admin Control Panel
IP Address : 62.255.192.162
Username : Hybr!d
Classname : vB_Database
MySQL Version : 5.1.58