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 @ 15:15
Script: /board.php?boardid=4&sid=e38297ca8a8c5dafd308aa77b97d23ca
Referer: http://stc-board.de/board.php?boardid=4&sid=e38297ca8a8c5dafd308aa77b97d23ca