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: 05.05.2024 @ 00:06
Script: /thread.php?goto=nextnewest&threadid=731&sid=5636bf9c1708ee82c0a1bf72d2a6c9cb
Referer: http://stc-board.de/thread.php?goto=nextnewest&threadid=731&sid=5636bf9c1708ee82c0a1bf72d2a6c9cb