Problemas ao usar a sintaxe heredoc no PHP [fechado]

<?php
        $output = <<< END 
        <table style="display: table;" class="listview rowstyle-rowhighlight" id="resourcegrid">
          <thead>
            <tr>
              <th width="70"></th>
              <th style="-moz-user-select: none;" class="sortable fd-column-0"><a class="fdTableSortTrigger" href="#">Name</a></th>
              <th style="-moz-user-select: none;" class="sortable fd-column-1"><a class="fdTableSortTrigger" href="#">Contributor</a></th>
              <th style="-moz-user-select: none;" class="sortable fd-column-3"><a class="fdTableSortTrigger" href="#">Modified</a></th>
            </tr>
          </thead><tbody>
END;

echo $output;

Quando eu executo relatórios:

Parse error: parse error on line 2

Mas não vejo nada de anormal.

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