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 ('7ebb2d04e3cc2551c47b055d10b19bf4', -1, 1566712471, 1566712471, '22eebdab', 2, 0, 0)

Line : 187
File : sessions.php