"Twitter API error for multiple user details extraction"

<?xml version="1.0" encoding="UTF-8"?><process version="7.6.001">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="7.6.001" expanded="true" name="Process">
    <process expanded="true">
      <operator activated="true" class="social_media:search_twitter" compatibility="7.3.000" expanded="true" height="68" name="Search Twitter" width="90" x="179" y="85">
        <parameter key="connection" value="TwitterConnection1"/>
        <parameter key="query" value="&quot;rapidminer&quot; -rt -http"/>
        <parameter key="limit" value="20"/>
        <parameter key="language" value="en"/>
      </operator>
      <operator activated="true" class="filter_examples" compatibility="7.6.001" expanded="true" height="103" name="Filter Examples" width="90" x="447" y="85">
        <list key="filters_list">
          <parameter key="filters_entry_key" value="Retweet-Count.ge.1"/>
        </list>
      </operator>
      <operator activated="true" breakpoints="after" class="select_attributes" compatibility="7.6.001" expanded="true" height="82" name="Select Attributes" width="90" x="648" y="85">
        <parameter key="attribute_filter_type" value="single"/>
        <parameter key="attribute" value="From-User"/>
      </operator>
      <operator activated="true" breakpoints="after" class="concurrency:loop_values" compatibility="7.6.001" expanded="true" height="82" name="Loop Values (2)" width="90" x="849" y="85">
        <parameter key="attribute" value="From-User"/>
        <process expanded="true">
          <operator activated="true" class="social_media:get_twitter_user_details" compatibility="7.3.000" expanded="true" height="68" name="Get Twitter User Details (2)" width="90" x="514" y="34">
            <parameter key="connection" value="NewConnection"/>
            <parameter key="user" value="%{loop_value}"/>
          </operator>
          <connect from_op="Get Twitter User Details (2)" from_port="output" to_port="output 1"/>
          <portSpacing port="source_input 1" spacing="0"/>
          <portSpacing port="source_input 2" spacing="0"/>
          <portSpacing port="sink_output 1" spacing="0"/>
          <portSpacing port="sink_output 2" spacing="0"/>
        </process>
      </operator>
      <operator activated="true" class="append" compatibility="7.6.001" expanded="true" height="82" name="Append" width="90" x="1050" y="85"/>
      <connect from_op="Search Twitter" from_port="output" to_op="Filter Examples" to_port="example set input"/>
      <connect from_op="Filter Examples" from_port="example set output" to_op="Select Attributes" to_port="example set input"/>
      <connect from_op="Select Attributes" from_port="example set output" to_op="Loop Values (2)" to_port="input 1"/>
      <connect from_op="Loop Values (2)" from_port="output 1" to_op="Append" to_port="example set 1"/>
      <connect from_op="Append" from_port="merged set" 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"/>
    </process>
  </operator>
</process>

I built an experiment in RapidMiner that does the following:

1) Using the 'Search Twitter', it searches twitter for keywords/queries

2) Using 'Filter keywords', it filters the results by number of retweets greater than 1

3) Using 'Selelect Attributes', it selects only the attribute 'From-User'

4) Using 'Loop Values' with emebedded 'Get Twitter user details', I extracted the user details of all users in (3) above

5) Using the 'Append' tool, I appended all the user details into 1

On running the experiment, it gave an error of 'Twitter API error' at the 'Get Twitter User Details' tool.

Not sure how to fix it, any help will be apreciated.

XML code of the experiment is attached: