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: 04.05.2024 @ 17:03
Script: /index.php?sid=755f1fa02a0a1263cee383a206431013
Referer: http://stc-board.de/index.php?sid=755f1fa02a0a1263cee383a206431013