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: 12.05.2024 @ 00:44
Script: /attachment.php?attachmentid=256&thumbnail=1&sid=2d8eadd9d5e36b3b2db0d7563f9765e8
Referer: http://stc-board.de/attachment.php?attachmentid=256&thumbnail=1&sid=2d8eadd9d5e36b3b2db0d7563f9765e8