Java FX 8 CSS ClassCastException

/* styles */

table {
  font-family: sans-serif;
  border-collapse: collapse;
  max-height: 300px;
  overflow: auto;
}

td,
th {
  border: 1px solid #ddd;
  text-align: left;
  padding: 8px;
  background: #fff;
}

tr:nth-child(odd) td {
  background-color: #eee;
}

/* fixed headers */

table,
thead,
tbody {
  display: block;
}

thead {
  position: sticky;
  top: 0;
}

tr {
  display: flex;
}

th,
td {
  flex: 1;
  min-width: 100px;
  overflow: hidden;
  text-overflow: ellipsis;
}

<h2>HTML Table</h2>
<div class=wrap>
  <table>
    <thead>
      <tr>
        <th>#</th>
        <th>Firstname</th>
        <th>Lastname</th>
        <th>Age</th>
        <th>City</th>
        <th>Country</th>
        <th>Sex</th>
        <th>Example</th>
        <th>Example</th>
        <th>ExampleReallyReallyLong</th>
        <th>Example</th>
      </tr>
    </thead>
    <tbody>
      <tr>
        <td>1</td>
        <td>Anna</td>
        <td>Pitt</td>
        <td>35</td>
        <td>New York</td>
        <td>USA</td>
        <td>Female</td>
        <td>Yes</td>
        <td>Yes</td>
        <td>Yes</td>
        <td>Yes</td>
      </tr>
      <tr>
        <td>1</td>
        <td>Anna</td>
        <td>Pitt</td>
        <td>35</td>
        <td>New York</td>
        <td>USA</td>
        <td>Female</td>
        <td>Yes</td>
        <td>Example Really Really Long</td>
        <td>ExampleReallyReallyLong</td>
        <td>Yes</td>
      </tr>
      <tr>
        <td>1</td>
        <td>Anna</td>
        <td>Pitt</td>
        <td>35</td>
        <td>New York</td>
        <td>USA</td>
        <td>Female</td>
        <td>Yes</td>
        <td>Yes</td>
        <td>Yes</td>
        <td>Yes</td>
      </tr>
      <tr>
        <td>1</td>
        <td>Anna</td>
        <td>Pitt</td>
        <td>35</td>
        <td>New York</td>
        <td>USA</td>
        <td>Female</td>
        <td>Yes</td>
        <td>Yes</td>
        <td>Yes</td>
        <td>Yes</td>
      </tr>
      <tr>
        <td>1</td>
        <td>Anna</td>
        <td>Pitt</td>
        <td>35</td>
        <td>New York</td>
        <td>USA</td>
        <td>Female</td>
        <td>Yes</td>
        <td>Yes</td>
        <td>Yes</td>
        <td>Yes</td>
      </tr>
      <tr>
        <td>1</td>
        <td>Anna</td>
        <td>Pitt</td>
        <td>35</td>
        <td>New York</td>
        <td>USA</td>
        <td>Female</td>
        <td>Yes</td>
        <td>Yes</td>
        <td>Yes</td>
        <td>Yes</td>
      </tr>
      <tr>
        <td>1</td>
        <td>Anna</td>
        <td>Pitt</td>
        <td>35</td>
        <td>New York</td>
        <td>USA</td>
        <td>Female</td>
        <td>Yes</td>
        <td>Yes</td>
        <td>Yes</td>
        <td>Yes</td>
      </tr>
      <tr>
        <td>1</td>
        <td>Anna</td>
        <td>Pitt</td>
        <td>35</td>
        <td>New York</td>
        <td>USA</td>
        <td>Female</td>
        <td>Yes</td>
        <td>Yes</td>
        <td>Yes</td>
        <td>Yes</td>
      </tr>
      <tr>
        <td>1</td>
        <td>Anna</td>
        <td>Pitt</td>
        <td>35</td>
        <td>New York</td>
        <td>USA</td>
        <td>Female</td>
        <td>Yes</td>
        <td>Yes</td>
        <td>Yes</td>
        <td>Yes</td>
      </tr>
    </tbody>
  </table>
</div>