title: Fatal error: Call to a member function setActive() on a non-object
body: <p>I am getting the following error on the backend of Magento:</p>
  
  <pre><code>Fatal error: Call to a member function setActive() on a non-object in /var/www/vhosts/pro-pin.ca/httpdocs/app/code/core/Mage/Adminhtml/Controller/Action.php on line 82
  </code></pre>
  
  <p>I've gone through the community forum, but found out that this was due to the magic slider or lightbox extensions. I haven't had this problem on any other server.</p>
  
  <p>Any help please.. </p>