phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('777b0421a24ad2888d2adcc0e2ac64b6', -1, 1490449022, 1490449022, '36c54a89', -9, 0, 0)

Line : 187
File : sessions.php