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: 09.05.2024 @ 00:09
Script: /addreply.php?postid=86528&sid=42fe54b8106a95c8b3dc6a9b159e5f7f
Referer: http://www.stc-board.de/addreply.php?postid=86528&sid=42fe54b8106a95c8b3dc6a9b159e5f7f