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 ('7bee93d3f43a33d92ee076b4edbd48ba', -1, 1406827999, 1406827999, '6b145b51', 19, 0)

Line : 174
File : sessions.php