I recently bought an Asustor 6704T. When I try to register the device either through the web interface, I get the error
Unable to connect to the ASUSTOR server. Please check your network settings and try again. (Ref. 5039)
If I try to register at https://member.asustor.com using a gmail or apple account, I get a blank page after clicking Next on the Confirming your information page.
This is my last ditch effort to try to get this to work, otherwise I think I will return the device.
Probably there's issues with your DNS. Check that out or try using Google's DNS 8.8.8.8 in the ADM Settings => Network => under General tab => DNS server.