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 @ 17:23
Script: /usercp.php?action=options_change&sid=32d74ed0d3a67f4fb79b051811cfa537
Referer: http://stc-board.de/usercp.php?action=options_change&sid=32d74ed0d3a67f4fb79b051811cfa537