title: MVC can't find controller action when invoked with @Html.RenderAction
body: <p>I'm trying to call an action from a different controller in an MVC 5 page: </p>
  
  <pre><code> Html.RenderAction("RenderHeader", "ParkDetailPage", new {...});
  </code></pre>
  
  <p>The error:</p>
  
  <p>System.Web.HttpException
  A public action method 'RenderHeader' was not found on controller 'xxx.Website.Controllers.ParkListerController'.</p>
  
  <p>The RenderHeader method is defined as:</p>
  
  <pre><code>public ActionResult RenderHeader(int parkId, List&lt;ParkDetailBlockBase&gt; menuItems = null, List&lt;string&gt; highlights = null)
  { 
    //....
    return PartialView("Partials/_Header", viewModel);
  }
  </code></pre>
  
  <p>What's the reason the controller name I use as the second argument is ignored?</p>