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: 05.05.2024 @ 10:05
Script: /index.php?sid=a2384db9c5c6bed0097e65daa9ab043f
Referer: http://stc-board.de/index.php?sid=a2384db9c5c6bed0097e65daa9ab043f