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: 02.05.2024 @ 06:59
Script: /calendar.php?sid=d8d7e90f4f6501e8c8634c5119095568
Referer: http://stc-board.de/calendar.php?sid=d8d7e90f4f6501e8c8634c5119095568