title: System.Web.Mvc.HtmlHelper<dynamic> does not contain a definition for 'Syncfusion' Error
body: <p>I'm working with ASP.Net MVC 3 with the Razor engine and version 9.104.0.20 of the SyncFusion mvc control suite.</p>
  
  <p>In the documentation for this control, I am to put lines of code similar to the below in my master page:</p>
  
  <pre><code>@Html.Syncfusion().ScriptManager()
  </code></pre>
  
  <p>Per the Syncfusion documentation and <a href="https://stackoverflow.com/questions/217350/why-dont-my-htmlhelper-extensions-work">this Stack Overflow suggestion</a>, I have made sure to add the namespaces to my web.config file under the  element.</p>
  
  <pre><code>   &lt;add namespace="Syncfusion.Mvc.Schedule"/&gt;
  </code></pre>
  
  <p>The solution builds but I get the following error when I run it:</p>
  
  <blockquote>
    <p>'System.Web.Mvc.HtmlHelper' does not contain a definition for 'Syncfusion' and no extension method 'Syncfusion' accepting a first argument of type 'System.Web.Mvc.HtmlHelper' could be found (are you missing a using directive or an assembly reference?)</p>
  </blockquote>
  
  <p>I don't think this issue has to do with Syncfusion but instead with my inability to reference their assemblies correctly.</p>
  
  <p>How do I address this?</p>