title: SSRS Hidden Expression in a Tablix throws an error but Tablix does not have a hidden expression configured
body: <p>I have a report that is throwing the following error:</p>
  
  <pre><code>    Error   2   [rsRuntimeErrorInExpression] The Hidden expression for the tablix ‘Tablix27’ 
      contains an error: 
      The query returned no rows for the dataset. The expression therefore 
      evaluates to null.      
  </code></pre>
  
  <p>Tablix 27 has <code>Visibility</code> set to <code>show</code> so there's no <code>hide expression</code>. Any idea on how to get rid of the error or any pointers that can lead me in the right direction? </p>
  
  <p>what could be causing the problem?</p>