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 ('81c28de4fe7137693e8e43d1fc74223b', -1, 1412077662, 1412077662, '36c4844a', 21, 0)

Line : 158
File : sessions.php