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 ('c3cf784e2f0d17c5b72a0c79c3550a2e', -1, 1490448698, 1490448698, '36c54a89', -9, 0, 0)

Line : 187
File : sessions.php