SQL-DATABASE ERROR

Database error in WoltLab Burning Board (): Link-ID == false, connect failed
mysql error: Unknown MySQL server host 'db850.1und1.de' (-2)
mysql error number: 2005
mysql version: unknown
php version: 4.4.9
Date: 29.11.2020 @ 20:17
Script: /acmelan/
Referer: