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 @ 12:05
Script: /login.php?sid=97acb0c66ead80a0f2af737b1600193e
Referer: http://www.stc-board.de/login.php?sid=97acb0c66ead80a0f2af737b1600193e