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: 28.04.2024 @ 12:30
Script: /board.php?boardid=4&sid=7c09bae97741fabea9cc6485ff0f7c49
Referer: http://stc-board.de/board.php?boardid=4&sid=7c09bae97741fabea9cc6485ff0f7c49