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: 28.04.2024 @ 17:03
Script: /index.php?sid=0f0b3235d6e3bc59e9aae7810894c3ee
Referer: http://stc-board.de/index.php?sid=0f0b3235d6e3bc59e9aae7810894c3ee