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: 30.04.2024 @ 07:32
Script: /calendar.php?sid=971047e2665bdf1a80377416a3c8a5b4
Referer: http://stc-board.de/calendar.php?sid=971047e2665bdf1a80377416a3c8a5b4