title: VM has become 'inaccessible' - Vagrant no longer working
body: <p>For some reason this morning when I run '<strong>vagrant up</strong>' I get the following error (this has worked absolutely fine for over a year)</p>
  
  <pre><code>Your VM has become "inaccessible". Unfortunately, this is a critical error with VirtualBox that Vagrant can not cleanly recover from. Please open VirtualBox and clear out your inaccessible virtual machines or find a way to fix them.
  </code></pre>
  
  <p>I could try removing my existing .vagrant folder and doing a vagrant up but that will take forever on our very slow internet speeds - can anyone suggest how to fix this quickly?</p>