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 @ 01:07
Script: /board.php?boardid=44&page=1&daysprune=1000&sortfield=vote&sortorder=ASC&sid=2fc1b2e2e947dd95051013e8c4d4d9c2
Referer: http://stc-board.de/board.php?boardid=44&page=1&daysprune=1000&sortfield=vote&sortorder=ASC&sid=2fc1b2e2e947dd95051013e8c4d4d9c2