phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 144 Table './forum_members/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) VALUES ('81b13c868a49b8bb56ab30dee9207b9d', -1, 1435619401, 1435619401, '36c6de81', 20, 0)

Line : 158
File : sessions.php