phpBB : Critical Error

Error doing DB query userdata row fetch

DEBUG MODE

SQL Error : 1194 Table 's' is marked as crashed and should be repaired

SELECT u.*, s.* FROM phpbb_sessions s, phpbb_users u WHERE s.session_id = '42a38f0d584827c39d71e6d23e478470' AND u.user_id = s.session_user_id

Line : 239
File : /home/ju34431/html/forum/includes/sessions.php