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: 29.04.2024 @ 16:05
Script: /calendar.php?sid=6d6a51571d70c41bad30e3d2f9e074eb
Referer: http://www.stc-board.de/calendar.php?sid=6d6a51571d70c41bad30e3d2f9e074eb