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: 01.05.2024 @ 23:57
Script: /profile.php?userid=225&sid=55dcfa10fc5a3264d7a13bf9fceb9439
Referer: http://stc-board.de/profile.php?userid=225&sid=55dcfa10fc5a3264d7a13bf9fceb9439