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 ('f03ae5ef2a42e9af47fc8711d3887cfa', -1, 1558825860, 1558825860, '03558fef', 15, 0, 0)

Line : 187
File : sessions.php