trang error

"Bruce D'Arcus" <[email protected]> Mon, 5 Apr 2004 14:47:11 -0400

Newsgroups	gmane.text.xml.relaxng.general
Message-ID	<[email protected]>

Am trying to convert an rnc file to xsd, but getting the below error.   
Can someone give me a hint on what's going on?

Bruce

Exception in thread "main" java.lang.NullPointerException
         at  
com.thaiopensource.relaxng.output.xsd.Transformer.getTransformedAttribut 
eGroup(Unknown Source)
         at  
com.thaiopensource.relaxng.output.xsd.Transformer.visitAttributeGroup(Un 
known Source)
         at  
com.thaiopensource.relaxng.output.xsd.basic.AttributeGroupDefinition.acc 
ept(Unknown Source)
         at  
com.thaiopensource.relaxng.output.xsd.basic.Schema.accept(Unknown  
Source)
         at  
com.thaiopensource.relaxng.output.xsd.basic.SchemaTransformer.transform( 
Unknown Source)
         at  
com.thaiopensource.relaxng.output.xsd.XsdOutputFormat.output(Unknown  
Source)
         at com.thaiopensource.relaxng.translate.Driver.doMain(Unknown  
Source)
         at com.thaiopensource.relaxng.translate.Driver.main(Unknown  
Source)