title: application pool stopped on webrequest
body: <p>I have a site that has been working fine for months. This morning I started getting 503 Service Unavailable errors. After checking IIS, I noticed that the application pool is being stopped. Since I had issues with it before, I suspected WebRequest to be the problem. So I commented out the WebRequest portion of the site, and guess what, the application pool no longer gets disabled. I suspect there has been another security update and I can't figure out what else I need to do to get the WebRequest to work again.</p>
  
  <p>Things I have already tried:<br>
  1) aspnet_regiis -u then -i <br>
  2) reinstalling .net framework<br>
  <br>More info: I use <strong>NetworkService</strong> account for the <strong>asp.net v4.0</strong> app pool with <strong>Windows Authentication</strong></p>
  
  <p>The error from the event log is this:<br>
  <strong>"HipIISEngineStub.dll failed to load. The data is the error."</strong></p>
  
  <pre><code>var request = (HttpWebRequest)WebRequest.Create(path1);
  request.Credentials = CredentialCache.DefaultCredentials;
  request.PreAuthenticate = true;            
  
  var getResponse = new Func&lt;WebRequest, WebResponse&gt;(req =&gt; req.GetResponse());
  
  try
  {
      return getResponse(request).GetResponseStream();
  }
  </code></pre>