Windows Phone/Silverlight application The type or namespace name 'XmlTextReader' could not be found (are you missing a using directive or an assembly reference?)

Windows Phone/Silverlight application The type or namespace name 'XmlTextReader' could not be found (are you missing a using directive or an assembly reference?)

XmlTextReader or XmlDocument aren't supported in Silverlight. Hence use XMLReader for reading XMLDocuments

See also:
How to Add/Load XAML Dynamically to RichTextBox Control - Windows Phone Development C#/VB.NET

Create XML Files using .NET / Create XML Files using C#

Convert an XML file to HTML file using C#

How to Get All Elements of an XML using C# (.NET)

How to add XML Declaration to an XML document using C# (.NET)

Remove DOCTYPE declaration from XML Files using C#