phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('317e9aa6066bf5a0c8ae744321aad9ac', -1, 1438460019, 1438460019, '36c4f8ba', -1, 0, 0)

Line : 172
File : sessions.php