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: 28.04.2024 @ 15:51
Script: /calendar.php?sid=ddee316832b46b29127e21a4bb4bc189
Referer: http://www.stc-board.de/calendar.php?sid=ddee316832b46b29127e21a4bb4bc189