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: 10.05.2024 @ 08:15
Script: /formmail.php?userid=4&sid=cd9f76809a7e92b420b3df8e1b07bbe5
Referer: http://stc-board.de/formmail.php?userid=4&sid=cd9f76809a7e92b420b3df8e1b07bbe5