"Error using Linear Regression with R Extension"

I am experimenting with the R extension.  I can successfully do a simple linear regression using the R Script operator, but I cannot do the linear regression using the R linear regression operator.  When I use the R Linear Regression operator I get the following error:

Process Failed:  The model did not return any results, so no prediction can be made.  During model application the data is exported to R and needs to be scored there.  The scored data should then be transferred back to RapidMiner but wasn't available.  Offending operator:  Apply Model.

Any help is appreciated.

Here is the XML for my process:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<process version="5.3.015">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="5.3.015" expanded="true" name="Process">
    <process expanded="true">
      <operator activated="true" class="quantx1:world_bank_data_extractor" compatibility="1.0.006" expanded="true" height="60" name="World Bank Data Extractor (2)" width="90" x="45" y="30">
        <parameter key="Select Indicator" value="SP.POP.TOTL"/>
        <parameter key="Start Year" value="1950"/>
        <parameter key="End Year" value="2000"/>
        <parameter key="Country" value="Germany"/>
      </operator>
      <operator activated="true" class="select_attributes" compatibility="5.3.015" expanded="true" height="76" name="Select Attributes (2)" width="90" x="179" y="30">
        <parameter key="attribute_filter_type" value="subset"/>
        <parameter key="attributes" value="|Year|Value"/>
      </operator>
      <operator activated="true" class="set_role" compatibility="5.3.015" expanded="true" height="76" name="Set Role" width="90" x="313" y="30">
        <parameter key="attribute_name" value="Value"/>
        <parameter key="target_role" value="label"/>
        <list key="set_additional_roles"/>
      </operator>
      <operator activated="true" class="multiply" compatibility="5.3.015" expanded="true" height="94" name="Multiply" width="90" x="447" y="30"/>
      <operator activated="true" class="subprocess" compatibility="5.3.015" expanded="true" height="76" name="Example 4" width="90" x="581" y="120">
        <process expanded="true">
          <operator activated="true" class="set_role" compatibility="5.3.015" expanded="true" height="76" name="Set Role (4)" width="90" x="112" y="30">
            <parameter key="attribute_name" value="Year"/>
            <list key="set_additional_roles">
              <parameter key="Value" value="label"/>
            </list>
          </operator>
          <operator activated="true" class="r:linear_regression" compatibility="5.3.000" expanded="true" height="76" name="Linear Regression (3)" width="90" x="246" y="30"/>
          <operator activated="true" class="generate_data_user_specification" compatibility="5.3.015" expanded="true" height="60" name="Predict Year (2)" width="90" x="112" y="120">
            <list key="attribute_values">
              <parameter key="Year" value="2025"/>
            </list>
            <list key="set_additional_roles"/>
          </operator>
          <operator activated="true" class="apply_model" compatibility="5.3.015" expanded="true" height="76" name="Apply Model (3)" width="90" x="380" y="75">
            <list key="application_parameters"/>
          </operator>
          <connect from_port="in 1" to_op="Set Role (4)" to_port="example set input"/>
          <connect from_op="Set Role (4)" from_port="example set output" to_op="Linear Regression (3)" to_port="training set"/>
          <connect from_op="Linear Regression (3)" from_port="model" to_op="Apply Model (3)" to_port="model"/>
          <connect from_op="Predict Year (2)" from_port="output" to_op="Apply Model (3)" to_port="unlabelled data"/>
          <connect from_op="Apply Model (3)" from_port="labelled data" to_port="out 1"/>
          <portSpacing port="source_in 1" spacing="0"/>
          <portSpacing port="source_in 2" spacing="0"/>
          <portSpacing port="sink_out 1" spacing="0"/>
          <portSpacing port="sink_out 2" spacing="0"/>
        </process>
      </operator>
      <operator activated="true" class="subprocess" compatibility="5.3.015" expanded="true" height="76" name="Example 3" width="90" x="581" y="30">
        <process expanded="true">
          <operator activated="true" class="set_role" compatibility="5.3.015" expanded="true" height="76" name="Set Role (3)" width="90" x="112" y="30">
            <parameter key="attribute_name" value="Year"/>
            <list key="set_additional_roles"/>
          </operator>
          <operator activated="true" class="generate_data_user_specification" compatibility="5.3.015" expanded="true" height="60" name="Predict Year" width="90" x="112" y="120">
            <list key="attribute_values">
              <parameter key="Year" value="2025"/>
            </list>
            <list key="set_additional_roles"/>
          </operator>
          <operator activated="true" class="r:execute_script_r" compatibility="5.3.000" expanded="true" height="94" name="Execute Script (R)" width="90" x="246" y="30">
            <parameter key="script" value="dat &lt;- data.frame(dat)&#10;newdat &lt;- data.frame(predict_yr)&#10;prediction &lt;- predict(lm(Value~Year,data=dat),newdata=newdat)&#10;results &lt;- data.frame(cbind(newdat,prediction))&#10;names(results) &lt;- c(&quot;Year&quot;,&quot;Value&quot;)&#10;results&#10;"/>
            <enumeration key="inputs">
              <parameter key="name_of_variable" value="dat"/>
              <parameter key="name_of_variable" value="predict_yr"/>
            </enumeration>
            <list key="results">
              <parameter key="results" value="Data Table"/>
            </list>
          </operator>
          <connect from_port="in 1" to_op="Set Role (3)" to_port="example set input"/>
          <connect from_op="Set Role (3)" from_port="example set output" to_op="Execute Script (R)" to_port="input 1"/>
          <connect from_op="Predict Year" from_port="output" to_op="Execute Script (R)" to_port="input 2"/>
          <connect from_op="Execute Script (R)" from_port="output 1" to_port="out 1"/>
          <portSpacing port="source_in 1" spacing="0"/>
          <portSpacing port="source_in 2" spacing="0"/>
          <portSpacing port="sink_out 1" spacing="0"/>
          <portSpacing port="sink_out 2" spacing="0"/>
        </process>
      </operator>
      <connect from_op="World Bank Data Extractor (2)" from_port="example set" to_op="Select Attributes (2)" to_port="example set input"/>
      <connect from_op="Select Attributes (2)" from_port="example set output" to_op="Set Role" to_port="example set input"/>
      <connect from_op="Set Role" from_port="example set output" to_op="Multiply" to_port="input"/>
      <connect from_op="Multiply" from_port="output 1" to_op="Example 3" to_port="in 1"/>
      <connect from_op="Multiply" from_port="output 2" to_op="Example 4" to_port="in 1"/>
      <connect from_op="Example 4" from_port="out 1" to_port="result 2"/>
      <connect from_op="Example 3" from_port="out 1" to_port="result 1"/>
      <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"/>
    </process>
  </operator>
</process>