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: 06.05.2024 @ 00:42
Script: /index.php?sid=3a1b61c9a0dc300a3a6542e85afc1a0e
Referer: http://stc-board.de/index.php?sid=3a1b61c9a0dc300a3a6542e85afc1a0e