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 @ 12:21
Script: /login.php?sid=43b673ce74f4f2430f6b947cd9200f7d
Referer: http://stc-board.de/login.php?sid=43b673ce74f4f2430f6b947cd9200f7d