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: 05.05.2024 @ 20:18
Script: /usercp.php?action=options_change&sid=b655a9f7d9195994ab4f82f40b35a13f
Referer: http://stc-board.de/usercp.php?action=options_change&sid=b655a9f7d9195994ab4f82f40b35a13f