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: 08.05.2024 @ 00:13
Script: /search.php?action=user&userid=291&sid=e7150f7a9a1f057d085f9a7e8339069e
Referer: http://stc-board.de/search.php?action=user&userid=291&sid=e7150f7a9a1f057d085f9a7e8339069e