If you are unable to point your domain name to our nameservers, the first thing you should do is check if you are entering them correctly. Please proceed to your client area. From there, press the "My Services" link, located on the left side of the page. This action is going to redirect you to your products page. Each of your products is going to be within a box section. In the middle of this box section, you are going to find your nameservers.
If you are entering them correctly and your registrar still does not accept them you are most likely using an uncommon domain name that has a specific requirement for the nameservers. An example of this is the .de TLD. For domains that have the .de TLD, you need to add nameservers that each resolve to a different IP address.
In such cases, please submit a ticket to our technical support team from your Client Area and provide them with the requirements for your domain's TLD.