SQL-DATABASE ERROR

Database error in WoltLab Burning Board (): Link-ID == false, connect failed
mysql error: Connection refused
mysql error number: 2002
mysql version: unknown
php version: 5.6.40-57+0~20211119.60+debian9~1.gbp8a9bd1
Date: 11.05.2024 @ 16:05
Script: /login.php?sid=a4b18a8b9efc6833171eb1d42e508c69
Referer: http://www.stc-board.de/login.php?sid=a4b18a8b9efc6833171eb1d42e508c69