XamlReader.Load and Parsing Behavior

Using the supplied XML namespace, and possibly additional non-default XML namespace information declared in the markup, object elements are evaluated and object names are used to construct objects. Attributes are used to find and set properties. If you provide markup that does not resolve within the Silverlight XAML vocabulary or any extended vocabulary, object creation and/or property setting will fail, a parsing exception is thrown, and the return value for Load will be null. The exception will only report the first error encountered in parse order, rather than a comprehensive validation.