UPDATE. This is amazing. If in the stuck command-line console I type exit (I see nothing written there) and press the carriage return, it boots after a few seconds into the VM Desktop. But every time that I reboot, the same happens. How to avoid booting into such command-line console each time? Thanks.
I posted the backup question before refreshing the screen as I was away from my desk for a bit. 
Have you in a Terminal or from the Command Line issued the following commands and then reboot?
sudo nvram boot-args=""
sudo shutdown -r now