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: 11.05.2024 @ 12:50
Script: /board.php?boardid=4&daysprune=1000&sortfield=views&sortorder=ASC&page=7&sid=2c8a0164b6579eb5c0d31bc1fa559995
Referer: http://www.stc-board.de/board.php?boardid=4&daysprune=1000&sortfield=views&sortorder=ASC&page=7&sid=2c8a0164b6579eb5c0d31bc1fa559995