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 @ 09:04
Script: /search.php?action=user&userid=239&sid=2b185a9460248238b6bfddeb56c1ecfe
Referer: http://stc-board.de/search.php?action=user&userid=239&sid=2b185a9460248238b6bfddeb56c1ecfe