phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 144 Table './forum_43/phpbb_sessions' is marked as crashed and last (automatic?) repair failed

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('4840f9ff7fdc2fbaf2aa2cd94c747739', -1, 1464083177, 1464083177, '36e01279', 8, 0, 0)

Line : 187
File : sessions.php