Deleted boards throwing error

I've been seeing constant errors where when we delete a board from the forum users will get given an error rather than a 404.

The error is then logged and reported back in daily e-mails with as follows:

Quote

- Attempt to read property "isPrivate" on null

The full error on a board that does this:

Error

• Error Type:

  wcf\system\exception\ErrorException

• Error Message:

  Attempt to read property "isPrivate" on null

• File:

  */lib/system/WCF.class.php (341)

• Template Context:

  PHP

  $this->foreachVars['fe56b14ff78d51443ed3b7dc3cf05bc714f1dde0']['item'] = $this->v['box'] ?? null;
  if ((is_countable($_foreach_fe56b14ff78d51443ed3b7dc3cf05bc714f1dde0) && count($_foreach_fe56b14ff78d51443ed3b7dc3cf05bc714f1dde0) > 0) || (!is_countable($_foreach_fe56b14ff78d51443ed3b7dc3cf05bc714f1dde0) && $_foreach_fe56b14ff78d51443ed3b7dc3cf05bc714f1dde0)) {
  foreach ($_foreach_fe56b14ff78d51443ed3b7dc3cf05bc714f1dde0 as $this->v['box']) {
  ?>
  ====> 					<?=$this->v['box']->render();?>
  				<?php }
  unset($this->v['box']);$this->v['box'] = $this->foreachVars['fe56b14ff78d51443ed3b7dc3cf05bc714f1dde0']['item'];
  unset($this->foreachVars['fe56b14ff78d51443ed3b7dc3cf05bc714f1dde0']); } ?>
  				
  				<?php

• Stack Trace:

  • #0 */forum/lib/system/box/BoardTagCloudBoxController.class.php (49):
  • wcf\system\WCF::handleError()
  • #1 */lib/system/box/AbstractBoxController.class.php (56):
  • wbb\system\box\BoardTagCloudBoxController->loadContent()
  • #2 */lib/system/box/AbstractBoxController.class.php (69):
  • wcf\system\box\AbstractBoxController->getContent()
  • #3 */lib/data/box/Box.class.php (335):
  • wcf\system\box\AbstractBoxController->hasContent()
  • #4 */lib/data/box/Box.class.php (316):
  • wcf\data\box\Box->hasContent()
  • #5 */templates/compiled/3_wcf_2_userException.php (1814):
  • wcf\data\box\Box->render()
  • #6 */lib/system/template/TemplateEngine.class.php (350):
  • include('*/templates/compiled/3_wcf_2_userException.php')
  • #7 */lib/system/exception/NamedUserException.class.php (43):
  • wcf\system\template\TemplateEngine->display()
  • #8 */lib/system/exception/IllegalLinkException.class.php (36):
  • wcf\system\exception\NamedUserException->show()
  • #9 */lib/system/request/RequestHandler.class.php (113):
  • wcf\system\exception\IllegalLinkException->show()
  • #10 */forum/index.php (11):
  • wcf\system\request\RequestHandler->handle()

System Information

• PHP Version:

  8.1.9

• WoltLab Suite Core:

  5.5.6

• Peak Memory Usage:

  3.515/128 MiB

• Request URI:

  GET /forum/board/3-imported-from-flarum/

• Referrer:

  https://mydomain.com/forum/thread/3146/

• User Agent:

  Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:106.0) Gecko/20100101 Firefox/106.0