Trying to get property 'posting_date' of non-object (View: C:\xampp\htdocs\ecampus\resources\views\classdetail.blade.php)

ErrorException (E_ERROR) Trying to get property 'posting_date' of non-object (View: C:\xampp\htdocs\ecampus\resources\views\classdetail.blade.php) Previous exceptions Trying to get property 'posting_date' of non-object (0)

<thead>
<tr>
<th scope="col">Sl</th>
<th scope="col" style="width: 20%">Publish date</th>
<th scope="col">Subject</th>
<th scope="col">Message</th>
<th scope="col">Message</th>
</tr>
</thead>
<tbody>    
<tr>
<td scope="row">  @php echo  $i++ ;  @endphp  </td>
<td></td>
<td></td>
<td></td>
<td>

via Chebli Mohamed