I have now checked out the “Schema Compliance” assertion. I can’t find much documentation around so I don’t know what it’s actually supposed to validate. To me it seems it doesn’t validate the XML-content in the response. I have tried to supply some xsd’s in the grammar section which it seems to ignore.
Regarding the original question I have finally figured out that also SoapUI cannot load the relevant schema factory. The message about this was hidden in a log and the assertion just showed that it worked.
I’m back to square on and will test the groovy based xml validation outside SoapUI and play around with libraries thereafter.
