Export ke PDF error

Ini errornya dimana?

 <?php

  require_once 'core/init.php';

  define('K_PATH_IMAGES', '');
  $pdf = new TCPDF(PDF_PAGE_ORIENTATION, PDF_UNIT, PDF_PAGE_FORMAT, TRUE, 'utf-8', FALSE);

  // Document Information
  $pdf->SetCreator('Sistem Informasi Sekolah');
  $pdf->SetTitle('Sistem Informasi');
  $pdf->SetSubject('Tutorial');

  // Header & Footer Data
  $pdf->SetHeaderData('template/assets/admin.png', 30, 'Laporan', 'Siswa', array(0, 0, 0,), array(0, 0, 0,));
  $pdf->SetFooterData(array(0, 0, 0,), array(0, 0, 0,));
  $pdf->SetHeaderFont(array(PDF_FONT_NAME_MAIN, '', PDF_FONT_SIZE_MAIN, '12'));
  $pdf->SetFooterFont(array(PDF_FONT_NAME_MAIN, '', PDF_FONT_SIZE_MAIN, '12'));

  $pdf->SetDefaultMonospacedFont(PDF_FONT_MONOSPACED);
  $pdf->SetMargins(PDF_MARGIN_LEFT, PDF_MARGIN_TOP, PDF_MARGIN_RIGHT);
  $pdf->SetHeaderMargin(PDF_MARGIN_HEADER);
  $pdf->SetFooterMargin(PDF_MARGIN_FOOTER);
  $pdf->SetAutoPageBreak(TRUE, PDF_MARGIN_BOTTOM);
  $pdf->setImageScale(PDF_IMAGE_SCALE_RATIO);
  $pdf->setFontSubsetting(TRUE);
  $pdf->SetFont('helvetica', '', 14, '', TRUE);
  $pdf->AddPage();
  $html = <<<EOF <h3>Pendaftaran Siswa Baru</h3>
   <h1>SMA</h1>

   <h4>Menu</h4>
   <nav>
     <ul>
       <li><a href="form-daftar.php">Daftar Baru</a></li>
       <li><a href="list-siswa.php">Pendaftar</a></li>
     </ul>
   </nav>
  EOF;

  $pdf->writeHTML($html, true, false, true, false, '');
  // $pdf->writeHTMLCell(0, 0, '', '', $html, 0, 1, 0, true, '', true);
  $pdf->Output('laporan.pdf', 'I');

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// END OF FILE
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