phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('8f8bf557a81682dd7cef1ec2cc59a336', -1, 1561050320, 1561050320, '3655a2d5', 33, 0, 0)

Line : 191
File : sessions.php