title: Defined expression in SSRS report is displaying #ERROR
body: <p>I have defined an expression in one of my cells from my <code>dataset1</code>. My Design window and I have to repeat for each month's cells but I'm getting an #ERROR when I click on the <code>PREVIEW</code> tab in SSRS.</p>
  
  <p>My thought is if the <code>ActivityMonth value = 1</code> and the <code>Type value = "PIF"</code> then display the value in the Data column.</p>
  
  <pre><code>=IIF(Fields!Activity_Month.Value = 1 AND Fields!Type.Value = "PIF", Fields!Data.Value, 0)
  </code></pre>
  
  <p>I got this WARNING from SSRS: </p>
  
  <blockquote>
    <p>[rsRuntimeErrorInExpression] The Value expression for the textrun ‘Textbox1471.Paragraphs[0].TextRuns[0]’ contains an error: Input string was not in a correct format. </p>
  </blockquote>
  
  <p>But it ran successfully.</p>