title: npm install Error: rollbackFailedOptional
body: <p>When I try <code>npm install</code> new packages it shows me this error:</p>
  
  <blockquote>
    <p>rollbackFailedOptional: verb npm-session 585aaecfe5f9a82</p>
  </blockquote>
  
  <pre><code>node --version
  8.4.0
  
  npm --version
  5.3.0
  </code></pre>