SQL-DATABASE ERROR

Database error in WoltLab Burning Board (): Link-ID == false, connect failed
mysql error: php_network_getaddresses: getaddrinfo failed: Temporary failure in name resolution
mysql error number: 2002
mysql version: unknown
php version: 5.6.40
Date: 30.11.2021 @ 03:08
Script: /calendar.php?sid=1d978c11182b2fcbe010221578ca1868
Referer: