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 @ 20:05
Script: /usercp.php?action=buddy&add=8&sid=de37ad885ef0f873fc113592a5f7adc1
Referer: http://stc-board.de/usercp.php?action=buddy&add=8&sid=de37ad885ef0f873fc113592a5f7adc1