I recently had some issues with my laptop that required Lenovo remoting in and molesting settings and ultimately resetting things.  Once again I ran into the nested virtualization not supported error.  At this point, I am pretty well practiced in this **bleep** of an error.  Went into windows 10 features and turned off "Virtual Machine Platform", rebooted and viola, it works again.

SInce I had to reboot anyway, I went ahead and made sure Intel VT-x was enabled in the BIOS.

I also made sure of my VM engine settings.