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: 09.05.2024 @ 12:07
Script: /board.php?boardid=28&sid=ff11cf5773332eb38263ec5d62ee48f6
Referer: http://www.stc-board.de/board.php?boardid=28&sid=ff11cf5773332eb38263ec5d62ee48f6