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: 29.04.2024 @ 00:14
Script: /attachment.php?attachmentid=342&thumbnail=1&sid=9b2e652447bae36367bab6c7d11e0419
Referer: http://stc-board.de/attachment.php?attachmentid=342&thumbnail=1&sid=9b2e652447bae36367bab6c7d11e0419