SQL-DATABASE ERROR

Database error in WoltLab Burning Board (2.3.6): Invalid SQL: DELETE FROM bb1_sessions WHERE userid='0' AND ipaddress = '54.196.189.229' AND useragent = 'CCBot/2.0 (http://commoncrawl.org/faq/)'
mysql error: Table 'bb1_sessions' is marked as crashed and should be repaired
mysql error number: 1194
mysql version: 5.1.73
php version: 5.3.3
Date: 22.07.2014 @ 21:28
Script: /wbb2/thread.php?postid=13513
Referer: