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: 28.04.2024 @ 20:12
Script: /board.php?boardid=52&page=1&daysprune=1000&sortfield=starter&sortorder=ASC&sid=d8a1021b85be162d14d4949a5689849c
Referer: http://stc-board.de/board.php?boardid=52&page=1&daysprune=1000&sortfield=starter&sortorder=ASC&sid=d8a1021b85be162d14d4949a5689849c