Why does XDocument.Load throw exception when ELMAH is enabled?

Question

I have the following code that retrieves a link to the latest post from the blog subsite:

XDocument doc = XDocument.Load("http://www.mysite.com/blog/syndication.axd");
XElement node = doc.Descendants("item").FirstOrDefault();
string text = node.Element("title").Value;
string uri = node.Element("link").Value;

The code always worked fine. This week I added ELMAH.MVC via NuGet as a Package Reference. As soon as I deploy the web.config file with the added ELMAH sections, I get the following error:

System.Web.HttpException (0x80004005): Error executing child request for handler 
'System.Web.Mvc.HttpHandlerUtil+ServerExecuteHttpHandlerAsyncWrapper'. 
---> System.Net.WebException: The remote server returned an error: (500) Internal Server Error.
   at System.Net.HttpWebRequest.GetResponse()
   at System.Xml.XmlDownloadManager.GetNonFileStream(Uri uri, ICredentials credentials, IWebProxy proxy, RequestCachePolicy cachePolicy)
   at System.Xml.XmlDownloadManager.GetStream(Uri uri, ICredentials credentials, IWebProxy proxy, RequestCachePolicy cachePolicy)
   at System.Xml.XmlUrlResolver.GetEntity(Uri absoluteUri, String role, Type ofObjectToReturn)
   at System.Xml.XmlReaderSettings.CreateReader(String inputUri, XmlParserContext inputContext)
   at System.Xml.XmlReader.Create(String inputUri, XmlReaderSettings settings, XmlParserContext inputContext)
   at System.Xml.Linq.XDocument.Load(String uri, LoadOptions options)

If I put the old web.config file back, the error goes away.

Any idea why adding ELMAH would cause XDocument.Load to fail?

Answer 1

You need to look at your ASP.Net site and find the server-side error.