XElement config = null;
using (
    var mrs = GetType().Assembly.GetManifestResourceStream(GetType().Namespace + ".RttRequestSkeleton.xml"))
{
    config = XElement.Load(mrs);
}

System.ArgumentNullException: Value cannot be null.
Parameter name: input
   at System.Xml.XmlReaderSettings.CreateReader(Stream input, Uri baseUri, String baseUriString, XmlParserContext inputContext)
   at System.Xml.XmlReader.Create(Stream input, XmlReaderSettings settings)
   at System.Xml.Linq.XElement.Load(Stream stream, LoadOptions options)
   at System.Xml.Linq.XElement.Load(Stream stream)