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: 10.05.2024 @ 00:27
Script: /memberslist.php?sid=bf2025ff8dcb10dbb5b99b2147a3c88b
Referer: http://stc-board.de/memberslist.php?sid=bf2025ff8dcb10dbb5b99b2147a3c88b