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: 15.05.2024 @ 00:04
Script: /thread.php?threadid=33&sid=2d9f61d0cc01eba4ba0ad70be2c44719
Referer: http://stc-board.de/thread.php?threadid=33&sid=2d9f61d0cc01eba4ba0ad70be2c44719