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: 28.04.2024 @ 15:26
Script: /board.php?boardid=44&sid=ad4c58cc9eb64fe9a4eb2873bf32293b
Referer: http://stc-board.de/board.php?boardid=44&sid=ad4c58cc9eb64fe9a4eb2873bf32293b