Vagrant box does not exist

[notatoad]

following the instructions at http://vccw.cc/#h2-2, i get the following message at the "vagrant box add" step:

$ vagrant box add vccw-team/xenial64 --name=vccw-team/xenial64

The box 'vccw-team/xenial64' could not be found or
could not be accessed in the remote catalog. If this is a private
box on HashiCorp's Atlas, please verify you're logged in via
`vagrant login`. Also, please double-check the name. The expanded
URL and error message are shown below:

URL: ["https://atlas.hashicorp.com/vccw-team/xenial64"]
Error: The requested URL returned error: 404 Not Found

Operating System: Ubuntu 16.04
Vagrant Version: 1.8.6
Virtual Box Version: 5.1.34

[lzivadinovic]

You can try few things, first is to update Vagrant because i guess it tries to fetch box from the old source list and second is simply define new source like here hashicorp/vagrant#9442 (comment)