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: 29.04.2024 @ 17:02
Script: /memberslist.php?letter=&sid=6d035b368f8e05e4014fe396587ce63d&sortby=homepage&order=ASC
Referer: http://stc-board.de/memberslist.php?letter=&sid=6d035b368f8e05e4014fe396587ce63d&sortby=homepage&order=ASC