phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO forum_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('d47d31e6e1d496f7371753dfdae7f07d', -1, 1540294529, 1540294529, '36e0387e', 9, 0, 0)

Line : 187
File : sessions.php