phpBB : Critical Error

Error doing DB query userdata row fetch

DEBUG MODE

SQL Error : 144 Table './schradthp/phpbb_sessions' is marked as crashed and last (automatic?) repair failed

SELECT u.*, s.* FROM phpbb_sessions s, phpbb_users u WHERE s.session_id = '1fc6e0056a4f9d63f8b3a2b554f46e6d' AND u.user_id = s.session_user_id

Line : 325
File : sessions.php