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 ('379fe6ad630d69c06174e06236213974', -1, 1425580795, 1425580795, '36577716', 1, 0)

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