Black screen when connecting to VM

I have been running Hyper-V on Windows 10 for close to a couple of years now.  Today, every time I attempt to log into the VM I get a black screen.  Sometimes, I can see the Windows desktop after a very long wait, but the start button doesn't work and there is nothing in the task bar.  Then, I get a pop-up that says "The application is not responding.  The program may respond again if you wait."  And it gives me the option to "end process.'  

Rebooting takes forever on the VM and it does the same thing again - black screen, very long wait, empty task bar... etc. 

Ending the process takes me back to the black screen.  Hyper-V Manager shows the VM is running.  

Any suggestions?

Thanks.