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 @ 06:51
Script: /calendar.php?sid=f559ece7e0e25a2c70924cc4f93e17a5
Referer: http://stc-board.de/calendar.php?sid=f559ece7e0e25a2c70924cc4f93e17a5