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 @ 11:16
Script: /index.php?sid=a37c6c6215edb3c52dc4ce6d47d2f714
Referer: http://stc-board.de/index.php?sid=a37c6c6215edb3c52dc4ce6d47d2f714