I ran across this error :
“An error occurred while attempting to connect to server …. Check That the Virtual machine Managment service is running and the you are authorzed to connect to the server
The Hyper-v management tool could not access an expected WMI class on computer …..”
this was a production cluster environment and After making sure that all the services are running, and there is no rights and permission errors, I have found ,running this command from console as Administartor , solving the problem :
After running this command the connection restored, reboot the server if it doesn’t connect right after .