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: 06.05.2024 @ 13:11
Script: /thread.php?threadid=838&sid=b5bc879bc88ce7f2b5d0baea1a91f5de
Referer: http://stc-board.de/thread.php?threadid=838&sid=b5bc879bc88ce7f2b5d0baea1a91f5de