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: 11.05.2024 @ 21:33
Script: /newthread.php?boardid=29&sid=a3b6d3321c9084a09dc0fd3e78c7498f
Referer: http://stc-board.de/newthread.php?boardid=29&sid=a3b6d3321c9084a09dc0fd3e78c7498f