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 ('a3b4f46fd6c20725f5446c34bbd7537c', -1, 1571113371, 1571113371, '03e3026d', -4, 0, 0)

Line : 191
File : sessions.php