Issue with sentiment analysis using AYLIEN extension

I intend to run a sentiment analysis on 25000 Tweets stored in an Excel file, to obtain the sentiment and polarity values. I try to do this using the AYLIEN extension 'Analyze sentiment'. Yesterday I successfully analyzed some of the Tweets, but today I only get questionmarks in the result field for sentiment and polarity. I have tried some of the actions previously proposed in the community such as changing 'sentiment mode', and it is not an API issue as my Tweets are already in an excel file. Can it be related to my license? I only today upgraded from free to educational version, as I thought the 10 000 row data limit was the issue. It still does not work though. What is strange is that it worked fine just yesterday. Is there any other viable solution? I'd be really thankful for any input or suggestion! The XML process and process design is posted below (the red error on the last operator was there also yesterday, I could still run it).

<?xml version="1.0" encoding="UTF-8"?><process version="8.2.000">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="8.2.000" expanded="true" name="Process">
    <process expanded="true">
      <operator activated="true" class="read_excel" compatibility="8.2.000" expanded="true" height="68" name="Read Excel" width="90" x="112" y="34">
        <parameter key="excel_file" value="C:\Users\Hjalmar\Documents\Master thesis\Data\Tweets (Excel)\Large Cap\AAPL\AAPL.test.xlsx"/>
        <parameter key="imported_cell_range" value="A1:B1000"/>
        <parameter key="first_row_as_names" value="false"/>
        <list key="annotations">
          <parameter key="0" value="Name"/>
        </list>
        <list key="data_set_meta_data_information">
          <parameter key="0" value="Date.true.polynominal.attribute"/>
          <parameter key="1" value="Tweet.true.text.attribute"/>
        </list>
      </operator>
      <operator activated="true" class="com.aylien.textapi.rapidminer:aylien_sentiment" compatibility="0.2.000" expanded="true" height="68" name="Analyze Sentiment" width="90" x="246" y="34">
        <parameter key="connection" value="Aylien"/>
        <parameter key="input_attribute" value="Tweet"/>
        <parameter key="sentiment_mode" value="document"/>
      </operator>
      <operator activated="true" class="write_excel" compatibility="8.2.000" expanded="true" height="82" name="Write Excel" width="90" x="447" y="34">
        <parameter key="excel_file" value="C:\Users\Hjalmar\Documents\Master thesis\Data\Sentiment\Large Cap\AAPL\AAPL.sentiment.test.xlsx"/>
      </operator>
      <connect from_op="Read Excel" from_port="output" to_op="Analyze Sentiment" to_port="Example Set"/>
      <connect from_op="Analyze Sentiment" from_port="Example Set" to_op="Write Excel" to_port="input"/>
      <portSpacing port="source_input 1" spacing="0"/>
      <portSpacing port="sink_result 1" spacing="0"/>
    </process>
  </operator>
</process>