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 ('e38cd5b2083cae92c2599f209a59b3b7', -1, 1553028160, 1553028160, '12d0d396', -4, 0, 0)

Line : 187
File : sessions.php