SQL-DATABASE ERROR

Database error in WoltLab Burning Board (): Link-ID == false, connect failed
mysql error: Unknown MySQL server host 'db960.1und1.de' (-2)
mysql error number: 2005
mysql version: unknown
php version: 5.2.17
Date: 12.05.2021 @ 13:54
Script: /wbb2/
Referer: