Finviz changed in the last days their screener table and now the headers of the table are in <th> instead of <td>, which makes the data and the headers of Screener class to be empty after constructing.

Before: <td class="table-top cursor-pointer" align="right" onclick="window.location='screener.ashx?v=111'">No.</td>
After: <th class="table-header cursor-pointer" align="right" onclick="window.location='screener.ashx?v=111'">No.</th>