Apply Model operator throwing null pointer exception

Hi,
I am providing Prediction Model generated by HMM Baum-Welch Learner  and ExampleSet by selecting one attribute from excel  to Apply model operator
but Apply Model throws an null pointer exception.
The XML of process is as follows:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<process version="5.1.014">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="5.1.014" expanded="true" name="Process">
    <process expanded="true" height="431" width="683">
      <operator activated="true" class="hmm:jahmm_reader" compatibility="5.0.000" expanded="true" height="60" name="JAHMM Model Reader" width="90" x="45" y="165">
        <parameter key="model_file" value="C:\Users\rohanu\Desktop\TEST.txt"/>
      </operator>
      <operator activated="true" class="read_excel" compatibility="5.1.014" expanded="true" height="60" name="Read Excel" width="90" x="45" y="30">
        <parameter key="excel_file" value="C:\Users\rohanu\Desktop\TEST.xls"/>
        <list key="annotations"/>
        <list key="data_set_meta_data_information">
          <parameter key="0" value="Test.true.text.attribute"/>
        </list>
      </operator>
      <operator activated="true" class="multiply" compatibility="5.1.014" expanded="true" height="94" name="Multiply" width="90" x="179" y="165"/>
      <operator activated="true" class="hmm:hmm_baum_welch" compatibility="5.0.000" expanded="true" height="76" name="HMM Baum-Welch Learner" width="90" x="313" y="30">
        <parameter key="observation_attribute" value="Test"/>
      </operator>
      <operator activated="true" class="read_excel" compatibility="5.1.014" expanded="true" height="60" name="Read Excel (2)" width="90" x="45" y="300">
        <parameter key="excel_file" value="C:\Users\rohanu\Desktop\GETEG.xls"/>
        <list key="annotations"/>
        <list key="data_set_meta_data_information">
          <parameter key="0" value="Test.true.text.attribute"/>
        </list>
      </operator>
      <operator activated="true" class="select_attributes" compatibility="5.1.014" expanded="true" height="76" name="Select Attributes (2)" width="90" x="313" y="300">
        <parameter key="attribute_filter_type" value="single"/>
        <parameter key="attribute" value="Test"/>
        <parameter key="attributes" value="Gender|Name1|"/>
      </operator>
      <operator activated="true" class="apply_model" compatibility="5.1.014" expanded="true" height="76" name="Apply Model" width="90" x="514" y="210">
        <list key="application_parameters"/>
      </operator>
      <connect from_op="JAHMM Model Reader" from_port="output" to_op="Multiply" to_port="input"/>
      <connect from_op="Read Excel" from_port="output" to_op="HMM Baum-Welch Learner" to_port="training set"/>
      <connect from_op="Multiply" from_port="output 1" to_op="HMM Baum-Welch Learner" to_port="HMM model"/>
      <connect from_op="Multiply" from_port="output 2" to_port="result 1"/>
      <connect from_op="HMM Baum-Welch Learner" from_port="model" to_op="Apply Model" to_port="model"/>
      <connect from_op="Read Excel (2)" from_port="output" to_op="Select Attributes (2)" to_port="example set input"/>
      <connect from_op="Select Attributes (2)" from_port="example set output" to_op="Apply Model" to_port="unlabelled data"/>
      <connect from_op="Apply Model" from_port="labelled data" to_port="result 2"/>
      <connect from_op="Apply Model" from_port="model" to_port="result 3"/>
      <portSpacing port="source_input 1" spacing="0"/>
      <portSpacing port="sink_result 1" spacing="0"/>
      <portSpacing port="sink_result 2" spacing="0"/>
      <portSpacing port="sink_result 3" spacing="0"/>
      <portSpacing port="sink_result 4" spacing="0"/>
    </process>
  </operator>
</process>


Please help !!