SQL-DATABASE ERROR

Database error in WoltLab Burning Board (2.3.6): Invalid SQL: select username from db_users where userid='1'
mysql error: Table 'arcade.db_users' doesn't exist
mysql error number: 1146
mysql version: 5.1.61-0+squeeze1
php version: 5.3.3-7+squeeze8
Date: 19.05.2012 @ 13:20
Script: /rpg_index.php
Referer: