phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 144 Table './gurudb/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, is_robot, session_admin) VALUES ('b78002c547c09aef2fc2e5401177832c', -1, 1467380017, 1467380017, '36a2dcb0', 10, 0, '0', 0)

Line : 174
File : sessions.php