title: Getting "Sys.ArgumentException: Value must not be null for Controls and Behaviors. Parameter name: element" in AJAX Control Toolkit
body: <p>I am using AJAX control toolkit accordion on my page. It's working fine on firefox and chrome but gives error on IE.
  Below is the code for accordion control :</p>
  
  <pre><code>&lt;ATK:Accordion ID="MyAccordion" runat="Server" SelectedIndex="-1" HeaderCssClass="accordionHeader"
      HeaderSelectedCssClass="accordionHeaderSelected" ContentCssClass="accordionContent"
      AutoSize="None" FadeTransitions="true" TransitionDuration="250" FramesPerSecond="40"
      RequireOpenedPane="false" SuppressHeaderPostbacks="true"&gt;
      &lt;Panes&gt;
          &lt;ATK:AccordionPane ID="AccordionPane4" runat="server"&gt;
              &lt;Header&gt;
                  &lt;asp:Literal ID ="Literal38" runat="server" Text="&lt;%$ Resources:BF_Resources, SITE_HolidayExceptionAccordian %&gt;"&gt;&lt;/asp:Literal&gt; 
              &lt;/Header&gt;
              &lt;Content&gt;...
  </code></pre>
  
  <p>And below is the error on UI :
  <a href="https://i.stack.imgur.com/u1jFF.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/u1jFF.png" alt="enter image description here"></a></p>