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 ('8d6fcebb68e5d2ed69b148a5ed8c7fd6', -1, 1511148798, 1511148798, '365092fb', 0, 0, 0)

Line : 187
File : sessions.php