Disable VT-X in Vagrantfile

gistfile1.txt

config.vm.provider :virtualbox do |vb|  
  vb.customize ["modifyvm", :id, "--hwvirtex", "off"]     
end

This is generally a solution to

The guest machine entered an invalid state while waiting for it
to boot. Valid states are 'starting, running'. The machine is in the
'poweroff' state. Please verify everything is configured
properly and try again.

If the provider you're using has a GUI that comes with it,
it is often helpful to open that and watch the machine, since the
GUI often has more helpful error messages than Vagrant can retrieve.
For example, if you're using VirtualBox, run vagrant up while the
VirtualBox GUI is open.

Thanks for sharing! works for me!

This does not seem to work any longer, unfortunately.

still works for me, added v.cpus = 1 to my Vagrantfile just to make sure

Thank you @ex3m1024 for this info!!!