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: 03.05.2024 @ 00:26
Script: /search.php?action=user&userid=39&sid=4d799d5dfe663f76e5b9a8c7606f9c90
Referer: http://stc-board.de/search.php?action=user&userid=39&sid=4d799d5dfe663f76e5b9a8c7606f9c90