Sushil,
Here is more clarification to my statement,
It means the XML data after parsing with the XMLNodeToDocument output which maps the IS DocumentReference and this ultimately maps to the object of the validate service and so this document/fields (datatypes)might not matching/incorrect format with the XML Schema(conformsTo).So validate service is throwing that error which has not a valid datatype exist in that mapped IS Document.
So check in the pipeline of the Document(IDATA) before mapping to the validate service.
I have seen this error before and so i composed it.
HTH,
RMG
#Integration-Server-and-ESB#webMethods#Flow-and-Java-services