This error happens when your NVR is not correctly configured to communicate with the HiDDNS service. Follow the instructions below to configure it correctly.
Ensure the NVR is connected to the internet via a network cable
Connect a mouse and a monitor directly to the NVR
Login to the menu and navigate to the Configuration option
Click on Network and then General tab
In the Preferred DNS field enter 126.96.36.199 and in the alternative DNS field enter 188.8.131.52 and click apply
You may need to restart the NVR for the above settings to apply successfully
Click the DDNS tab
Your NVR should now be registered with HiDDNS service.
If you try to use a name/domain that is already in use the NVR will tell you, and you will need to use a different domain.
You don't need to use hik-online's web page for this to work.