phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 144 Table './unitedheroes/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 ('9fe38c76b06202374afc0cfe646c85d3', -1, 1508711678, 1508711678, '36a7fa40', 4, 0, 0)

Line : 187
File : sessions.php