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 @ 23:27
Script: /thread.php?threadid=187&threadview=0&hilight=&hilightuser=0&page=9&sid=0cb1a48dba7e8d6f941189672abc56d5
Referer: http://stc-board.de/thread.php?threadid=187&threadview=0&hilight=&hilightuser=0&page=9&sid=0cb1a48dba7e8d6f941189672abc56d5