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: 02.05.2024 @ 06:57
Script: /markread.php?boardid=54&sid=ed8675724741723b9df9169111bb0d4a
Referer: http://www.stc-board.de/markread.php?boardid=54&sid=ed8675724741723b9df9169111bb0d4a