phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 144 Table './forum/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 ('c26b776b0c689d2681b8cef34ad04e20', -1, 1498577007, 1498577007, '3691607a', 0, 0, 0)

Line : 187
File : sessions.php