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: 05.05.2024 @ 15:51
Script: /search.php?action=user&userid=255&sid=8a024dade380cb017ed74cbc30c66cd1
Referer: http://stc-board.de/search.php?action=user&userid=255&sid=8a024dade380cb017ed74cbc30c66cd1