I recently ran into an issue whilst trying to change the nameservers for a German (.de) domain name. When I tried to point the domain to a whm/cpanel install I got the error 'Failed to Modify Domain Nameservers: The domain DNS check has failed'. The reason for this is specific to .de domains. There is a requirement for .de domains that the nameservers do not use the same ip address. Most dedicated or virtual servers only have one ip address attached, so if you are also using the same system to create the nameservers (needed to use cpanels dns functions) they will also be using the same ip address. I'm not sure how this is regulated amongst registrars, but I was dealing with a domain in a domainbox.net account and when trying to make the nameserver change I got the error message without any further information. After a bit of research I foud the following site which can be used to test if your nameservers comply with the regulations: https://www.denic.de/service/tools/nast/ The simplest fix for me was to use the DNS system provide by domainbox (3 nameservers with different ip addresses), and then point the A records for the domain to the cpanel instance (I needed to create the DNS zone in the system before it was possible to change the nameservers to use it or the same message appeared).