XmlTextWriter[
^] is defined in
System.Xml
namespace. Did you import it? More precisely, do you have a
Imports System.Xml
near the top of your .vb file?
If you do not want to import this namespace, you have to use the fully qualified name of the class to use it:
Dim tr As System.Xml.XmlTextWriter = New System.Xml.XmlTextWriter("D:\My Documents on D\Visual Studio Projects\Match Management Application\Players.xml", Nothing)