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: 10.05.2024 @ 01:18
Script: /thread.php?threadid=827&threadview=0&hilight=&hilightuser=0&page=12&sid=18fe5c80a9f28dde171318f309d52693
Referer: http://stc-board.de/thread.php?threadid=827&threadview=0&hilight=&hilightuser=0&page=12&sid=18fe5c80a9f28dde171318f309d52693