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: 06.05.2024 @ 01:04
Script: /index.php?sid=d25d9d8e519c97b74cd9336c1a057d3b
Referer: http://stc-board.de/index.php?sid=d25d9d8e519c97b74cd9336c1a057d3b