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: 02.05.2024 @ 20:22
Script: /thread.php?threadid=827&threadview=0&hilight=&hilightuser=0&sid=d8bf074a59073cfa8f8543d32b8d66f5&page=5
Referer: http://stc-board.de/thread.php?threadid=827&threadview=0&hilight=&hilightuser=0&sid=d8bf074a59073cfa8f8543d32b8d66f5&page=5