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: 02.05.2024 @ 20:09
Script: /memberslist.php?letter=&sortby=userposts&order=DESC&sid=e0ffad50e1ccf1275662375ccc30a6a7
Referer: http://stc-board.de/memberslist.php?letter=&sortby=userposts&order=DESC&sid=e0ffad50e1ccf1275662375ccc30a6a7