SQL-DATABASE ERROR

Database error in WoltLab Burning Board (): Link-ID == false, connect failed
mysql error:
mysql error number:
mysql version: unknown
php version: 7.2.34-36+ubuntu18.04.1+deb.sury.org+1
Date: 28.11.2023 @ 19:37
Script: /forum/board.php?boardid=4&sid=f6269ce7002320c56fa3c38a8d5078e6
Referer: