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: 07.05.2024 @ 12:24
Script: /thread.php?threadid=868&threadview=0&hilight=&hilightuser=0&sid=adf1bb9c874f4a1e82a5c5ac1a8f15a2&page=1
Referer: http://stc-board.de/thread.php?threadid=868&threadview=0&hilight=&hilightuser=0&sid=adf1bb9c874f4a1e82a5c5ac1a8f15a2&page=1