title: How to fix "A virtual path is expected" from HttpServerUtility.TransferRequest?
body: <p>In a custom class derived from System.Web.Mvc.ActionResult, I have the following line of code:</p>
  
  <pre><code>HttpContext.Current.Server.TransferRequest(myUrl, true);
  </code></pre>
  
  <p>In most situations, this works fine. But occasionally, it fails with the error:</p>
  
  <pre><code>Uncaught error in MVC Controller
  ArgumentException: Invalid path for child request 'http://[...]'. A virtual path is expected.
  </code></pre>
  
  <p>How can I fix this error?</p>