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: 03.05.2024 @ 00:44
Script: /index.php?sid=b1b1a5a7a1cc7cd6f0ba7a49a4db679a
Referer: http://stc-board.de/index.php?sid=b1b1a5a7a1cc7cd6f0ba7a49a4db679a