XDocument.Load(url) Error: Data at the root level is invalid. Line 1 position 1

Question

I am trying to read an xml document served on a webpage. Let's say that the url is "http://myfirsturl.com". The xml document at that url seems fine.

        try
        {
            string url = "http://myfirsturl.com";

            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);

            HttpWebResponse response = (HttpWebResponse)request.GetResponse();

            Stream stream = response.GetResponseStream();

            using (XmlReader reader = 
                 XmlReader.Create(new StreamReader(stream))
            {
                var doc = XDocument.Load(reader);
                Console.WriteLine(doc);
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex);
        }

I keep getting the following error:

   System.Xml.XmlException: Data at the root level is invalid. Line 1, position 1.
   at System.Xml.XmlTextReaderImpl.Throw(Exception e)
   at System.Xml.XmlTextReaderImpl.Throw(String res, String arg)
   at System.Xml.XmlTextReaderImpl.ParseRootLevelWhitespace()
   at System.Xml.XmlTextReaderImpl.ParseDocumentContent()
   at System.Xml.XmlTextReaderImpl.Read()
   at System.Xml.Linq.XDocument.Load(XmlReader reader, LoadOptions options)
   at System.Xml.Linq.XDocument.Load(XmlReader reader)

I have tried the exact same code with a different url and it works for example on: "http://mysecondurl.com".

I need help for steps on what to do next...

I have looked into the error and found two possible directions for a solution:

The encoding of the XML returns extra characters (I don't know how to check this)
The webpage is blocking the request. (I don't know how to tackle this)

Thanks for your time and help :)

If you can download the xml, an easy way to check the encoding (that usually works for me) is to open it in notepad. Click Save As and the current encoding should be displayed on the bottom. Probably not the best way, I'm sure. But you can at least try. — Broots Waymb, Apr 19 '16 at 13:41
Try http://stackoverflow.com/questions/17795167/xml-loaddata-data-at-the-root-level-is-invalid-line-1-position-1 to detect and remove a BOM — Alex K., Apr 19 '16 at 13:47
There is another option. You may not be getting an xml document, you could be getting a 500 error, or a 401, 404, etc, in which case you are getting an HTML response. You say the xml at the url looks fine, how have you checked it? — Crowcoder, Apr 19 '16 at 15:21
You need to provide a [mcve], really. Without the actual URL or XML you're using any answer is just a stab in the dark. — Charles Mager, Apr 19 '16 at 16:54

score 0 · Accepted Answer · answered May 10 '16 at 10:47

All I had to do was to set the headers to accept xml like so:

        try
        {
            string url = "http://myfirsturl.com";
            var request = (HttpWebRequest)WebRequest.Create(url);
            request.Accept = "application/xml"; // <== THIS FIXED IT

            using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
            {
                using (Stream stream = response.GetResponseStream())
                {
                    XDocument doc = XDocument.Load(stream);
                    Console.WriteLine(doc);
                }
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex);
        }

Thanks for the comments and help!

I got Error: TrustFailure (The authentication or decryption has failed.) any idea how to solve it please ? — Hoby, Mar 12 '19 at 21:50

XDocument.Load(url) Error: Data at the root level is invalid. Line 1 position 1

1 Answers1