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: 29.04.2024 @ 16:46
Script: /login.php?sid=3910306f7b25b2bc8d70438c1c5b6326
Referer: http://www.stc-board.de/login.php?sid=3910306f7b25b2bc8d70438c1c5b6326