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 ('8fc4ca10d071d4a8113814db5a6f6b4d', -1, 1711709679, 1711709679, '03eee2a7', -9, 0, 0)

Line : 187
File : sessions.php