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: 03.05.2024 @ 14:54
Script: /board.php?boardid=4&sid=e7f2f95285e589d68640d6746c8dac53
Referer: http://stc-board.de/board.php?boardid=4&sid=e7f2f95285e589d68640d6746c8dac53