title: Unknown server tag "ajaxToolkit:HtmlEditorExtender"
body: <p>I am using ajaxcontrols and in that all controls are working well But I had not found any of the control named as HtmlEditorExtender so I had just copied this tag in .html page</p>
  
  <pre><code>&lt;%@ Register TagPrefix="ajaxToolkit" Namespace="AjaxControlToolkit" Assembly="AjaxControlToolkit"%&gt;
  
  
  &lt;ajaxToolkit:ToolkitScriptManager ID="ToolkitScriptManager1" runat="Server" /&gt;
  &lt;ajaxToolkit:HtmlEditorExtender TargetControlID="txtComments" runat="server" /&gt;
  &lt;asp:TextBox ID="txtComments" runat="server"&gt;&lt;/asp:TextBox&gt;
  </code></pre>
  
  <p>here  is working fine but the problem arises on  , then i downloaded <a href="http://www.nuget.org" rel="nofollow">Nuget.tool</a> on reading some of the problems facing just like me but still its not working </p>
  
  <p>what shall I do?</p>
  
  <p>My Web.config file is </p>
  
  <pre><code>  &lt;configuration&gt;
  
  &lt;system.web&gt;
  &lt;compilation debug="true" targetFramework="4.0"/&gt;
  
  &lt;pages&gt;
    &lt;controls&gt;
      &lt;add tagPrefix="ajaxToolkit" assembly="AjaxControlToolkit" namespace="AjaxControlToolkit" /&gt;
    &lt;/controls&gt;
    &lt;sanitizer defaultProvider="AntiXssSanitizerProvider"&gt;
      &lt;providers&gt;
        &lt;add name="AntiXssSanitizerProvider" type="AjaxControlToolkit.Sanitizer.HtmlAgilityPackSanitizerProvider" /&gt;
      &lt;/providers&gt;
    &lt;/sanitizer&gt;
  &lt;/pages&gt;
  &lt;/system.web&gt;
  &lt;/configuration&gt;
  </code></pre>