Empty VirtualBox.xml Error
It started as a normal windows update problem - out of disk space, when the user tried to run his virtual computer it gave an error "empty VirtualBox.xml."
Most of the time when a virtual machine hosted on an Oracle VirtualBox application has an error that is somewhat new I just always upgrade the VirtualBox application and voila the problem will be fixed, but not this time around.
But when I tried to delete the VirtualBox.xml then I tried to run the virtual machine it fixed the problem. But after the empty error has been fixed another problem arises - intel virtualization is disabled.
Take note, before the update the virtual machine is running even if the intel virtualization is disabled in the BIOS. I guess some settings have changed in windows after the update.
Enabling intel virtualization in the BIOS solved the problem.