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 ('676b209545a85cbc597de9675e5b7f05', -1, 1398037330, 1398037330, '6b16785b', 19, 0)

Line : 174
File : sessions.php