phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 145 Table './mediest_phpbb/phpbb_sessions' is marked as crashed and should be repaired

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('bd90251cf083fcec6018fc2d755ae7a0', -1, 1409718819, 1409718819, '36c55f7f', 2, 0, 0)

Line : 187
File : sessions.php