Validating a Relax NG Schema
How to validate a Relax NG Schema
Because the MSXML parser does not support Relax NG Schemas you need to use another XML validator, for example Jing, Libxml2 or MSV. To validate a Relax NG Schema:
Open your Relax NG Schema in the XML Editor.
Click Tools > Jing or Tools > Libxml2 or Tools > MSV.
The Output Window is automatically displayed to show any errors in the Relax NG Schema.