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: 03.05.2024 @ 17:19
Script: /memberslist.php?sid=9dde7a7d5c6a7e8e3b3bf3411f5db7ce
Referer: http://stc-board.de/memberslist.php?sid=9dde7a7d5c6a7e8e3b3bf3411f5db7ce