title: Unable to downgrade Angular from version 6 to 5
body: <p>Recently (May 2018) newer stable version of angular has been released.
  I have migrated succesfully from version 5 to 6.</p>
  
  <p>But for some reason I wanted to rollback to version 5. I have tried following commands:</p>
  
  <pre><code>npm uninstall -g @angular/cli
  </code></pre>
  
  <p>it uninstalled the latest version of angular-6.</p>
  
  <pre><code>npm cache clean --force
  </code></pre>
  
  <p>and then installed</p>
  
  <pre><code>npm install -g @angular/cli@1.7.4
  </code></pre>
  
  <p>But it gave this error
  <a href="https://i.stack.imgur.com/MEsMo.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/MEsMo.png" alt="enter image description here"></a></p>
  
  <p><strong>node version</strong>: 8.10.0</p>
  
  <p><strong>npm version</strong>: 6.0.0</p>