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: 04.05.2024 @ 22:05
Script: /index.php?hidecat=3&sid=051f1fb6e8602d233c7e089e860caa7f
Referer: http://stc-board.de/index.php?hidecat=3&sid=051f1fb6e8602d233c7e089e860caa7f