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: 30.04.2024 @ 18:08
Script: /formmail.php?threadid=719&sid=23a6f3bac23f1b2ab313b5b8633c044b
Referer: http://stc-board.de/formmail.php?threadid=719&sid=23a6f3bac23f1b2ab313b5b8633c044b