phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 144 Table './phpbb/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 ('935c38469a0fb2e0808e4867af775c1f', -1, 1425272322, 1425272322, '321070c7', 2, 0, 0)

Line : 189
File : sessions.php