MyBB SQL Error

MyBB has experienced an internal SQL error and cannot continue.

SQL Error:
144 - Table './erasmus2/mybb_posts' is marked as crashed and last (automatic?) repair failed
Query:
SELECT u.*, u.username AS userusername, p.* FROM mybb_posts p LEFT JOIN mybb_users u ON (u.uid=p.uid) WHERE p.tid='2270' AND p.visible=1 ORDER BY p.dateline