MyBB SQL Error

MyBB has experienced an internal SQL error and cannot continue.

SQL Error:
144 - Table './sql15202/mybb_posts' is marked as crashed and last (automatic?) repair failed
Query:
SELECT f.style, f.overridestyle, p.* FROM mybb_forums f LEFT JOIN mybb_posts p ON(f.fid=p.fid) WHERE p.pid='151405' LIMIT 1