phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 144 Table './phpbb/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 ('3a3af327764406c0799e733c5178b8c6', -1, 1438748284, 1438748284, '36f28a18', -1, 0, 0)

Line : 189
File : sessions.php