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 @ 20:05
Script: /thread.php?threadid=794&goto=lastpost&sid=ba9bb0db52d1c8cf4b3f78824c10eeb1
Referer: http://stc-board.de/thread.php?threadid=794&goto=lastpost&sid=ba9bb0db52d1c8cf4b3f78824c10eeb1