phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 144 Table './phpbb_1/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 ('0a15cf95e16e5a8d008a99cc847f2ded', -1, 1425594461, 1425594461, '36522e26', 13, 0)

Line : 158
File : /forum/includes/sessions.php