Exception parsing: java.lang.NullPointerException

report=Originally I had both rdf:parseType="Resource" and rdf:type on the
<array> element and the validation service said only one of them should be
used, so I removed rdf:parseType and got the java exception.
RDF=<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
  <resource xmlns="https://localhost/#">
    <array rdf:type="http://localhost/obj1">
      <elements rdf:parseType="Collection">
        <element>
          <value rdf:datatype="http://www.w3.org/2001/XMLSchema#string
">abc</value>
        </element>
        <element>
          <value rdf:datatype="http://www.w3.org/2001/XMLSchema#double
">123.34</value>
        </element>
      </elements>
    </array>
  </resource>
</rdf:RDF>