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 @ 22:19
Script: /formmail.php?threadid=885&sid=e28545cf71ca2fb083e09e08d8c4628e
Referer: http://www.stc-board.de/formmail.php?threadid=885&sid=e28545cf71ca2fb083e09e08d8c4628e