cartodb-4.42/lib/assets/javascripts/builder/mustache-templates/infowindows_custom/infowindow_none.jst.mustache

<div class="CDB-infowindow Infowindow-none js-infowindow">
  <div class="CDB-infowindow-close js-close"></div>
  <div class="CDB-infowindow-container">
    <div class="CDB-infowindow-bg">
      <div class="CDB-infowindow-inner">
        <ul class="CDB-infowindow-list">
          <li class="CDB-infowindow-listItem">
            <h5 class="CDB-infowindow-subtitle"><%- _t('editor.layers.infowindow.select-fields') %></h5>
            <h4 class="CDB-infowindow-title"><%- _t('editor.layers.infowindow.no-fields') %></h4>
          </li>
        </ul>
      </div>
    </div>
    <div class="CDB-hook">
      <div class="CDB-hook-inner"></div>
    </div>
  </div>
</div>