In order for this plugin to work properly, the user needs to remove and re-add the necessary boxes:

vagrant plugin install vagrant-box-updater
vagrant box remove precise64
# `vagrant up` if using box_url config or...
vagrant box add precise64 http://files.vagrantup.com/precise64.box

We could try to explain this in the README, but might be simpler to create a rake task? That way, we could tell the user to run something like rake reinstall_basebox if they have that issue, and have something friendly like this run in the task:

if File.exists? File.expand_path("~/.vagrant.d/#{box_name}.stats")
  system "vagrant box remove #{box_name}"
  system "vagrant box add #{box_name} #{box_url}"
end

Even if they don't do this, the plugin won't crash the vagrant run -- it just won't do anything useful :)

👍 for a merge :)