title: The type or namespace name 'XmlDocument' could not be found. Are you missing an assembly reference?
body: <p>I'm trying to parse an xml document using the following:</p>
  
  <pre><code>XmlDocument doc = new XmlDocument ();
  doc.LoadXml (myXMLstring);
  </code></pre>
  
  <p>I get the error: </p>
  
  <blockquote>
    <p>The type or namespace name 'XmlDocument' could not be
    found. Are you missing an assembly reference?</p>
  </blockquote>
  
  <p>..even though I have
  using System.Xml;</p>
  
  <p>I'm not sure what an assembly reference is. I'm using Xamarin Studio. I see there are several folders for references. In the references folder for the base project I don't see an entry for System.Xml</p>
  
  <p>But in individual platforms I do see System.Xml in there.</p>
  
  <p>What can I do to get this error line to clear?</p>