phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' for key 2

INSERT INTO phpbb_datingforum_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in) VALUES ('272d01b8cb053f4271b013df56620fb9', -1, 1406601183, 1406601183, '36c4a84e', 9, 0)

Line : 174
File : sessions.php