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 ('a828b50966abcdd3d0100e3bcf7c989c', -1, 1566103685, 1566103685, '23af783b', 5, 0, 0)

Line : 172
File : sessions.php