I have some XML instances that I would like to validate against both a Relax NG schema and an XSD (for testing a re-engineering from XSD to Relax NG). I want to use the Saxon EE engine for the XSD, as the XSD schema is not valid according to Xerces (which is part of the motivation to switch to Relax NG), but gets through Saxon with some warnings. I have set the preferences to use Saxon as the default engine, and this works fine for batch validation ... until I include the xml-model processing instruction for the Relax NG schema in the instances. Then the XSD validation reverts to Xerces resulting in failure. I am using Oxygen 12.2. Is this a known bug? Has it been fixed in Oxygen 13 (this might give me the motivation to upgrade). Thanks, Tara