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 @ 14:03
Script: /memberslist.php?sid=ede9c18c92f5000b89f3ad7d17d69c6d
Referer: http://stc-board.de/memberslist.php?sid=ede9c18c92f5000b89f3ad7d17d69c6d