title: mPDF not generating PDF in firefox
body: <p>I am using <code>mPDF</code> library for creating PDF using html data.it works fine in <code>google chrome</code>,but in <code>firefox</code> it displays nothing.No files downloaded and no errors in console.</p>
  
  <p>Here is my code :</p>
  
  <pre><code>require_once( $destination_path."/mpdf/mpdf.php");
  $target_path = $destination_path . '/uploads/reports/';
  $htmlData='&lt;span&gt;Sample Html Content&lt;/span&gt;';
  try {
      $pdf= new mPDF();
      $pdf-&gt;debug = true;
      $pdf-&gt;SetFooter("MyApp" . '|{PAGENO}|' . date(DATE_RFC822));
      $pdf-&gt;WriteHTML($htmlData);
      $pdf-&gt;Output($fileOutputPath, 'F');
  }catch (Exception $e) {
      echo 'Caught exception: ',  $e, "\n";
  }
  </code></pre>
  
  <p>i am tried <code>ob_clean()</code> and <code>headers</code> for solve the issue,but it remains same .
  Anyone knows how to solve this issue?</p>