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 @ 17:48
Script: /login.php?sid=311f1617b410cc1cf9f5c8a3a09fe1b7
Referer: http://stc-board.de/login.php?sid=311f1617b410cc1cf9f5c8a3a09fe1b7