title: Why am I suddenly getting a "Blocked loading mixed active content" issue in Firefox?
body: <p>This morning, upon upgrading my Firefox browser to the latest version (from 22 to 23), some of the key aspects of my back office (website) stopped working.</p>
  
  <p>Looking at the Firebug log, the following errors were being reported:</p>
  
  <pre><code>Blocked loading mixed active content "http://code.jquery.com/ui/1.8.10/themes/smoothness/jquery-ui.css"
  Blocked loading mixed active content "http://ajax.aspnetcdn.com/ajax/jquery.ui/1.8.10/jquery-ui.min.js"`
  </code></pre>
  
  <p>among other errors caused by the latter of the two above not being loaded.</p>
  
  <p>What does the above mean and how do I resolve it?</p>