phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO bbs1_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in) VALUES ('87f78dcbfd07b3ac827b7b35f6516916', -1, 1408800056, 1408800056, '00000000', 1527, 0)

Line : 152
File : /home/purplebunny/html/bbs/includes/sessions.php