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: 11.05.2024 @ 10:58
Script: /calendar.php?sid=6fb7ecc4e60751f5f5a0edd1955976f6
Referer: http://stc-board.de/calendar.php?sid=6fb7ecc4e60751f5f5a0edd1955976f6