The above message pops up from time to time when attempting to remotely administer a Hyper-V server from another machine, particularly if the machine you are attempting to access is in another domain or in a workgroup.
First things first, make sure all of the config is correct on the Hyper-V server itself to allow remote administration. Use the excellent HVRemote for that 🙂
What usually catches me out after that is the fact that Hyper-V manager is not expecting a FQDN, it is hostname/shortname ONLY! Use the hosts file if you are having DNS issues.