TYPO3 Exception Viewhelpers after upgrade to v11

Question

After I have updated my TYPO3 System to v11.4 and PHP8, I recognized, that all my extensions, which include ViewHelpers are not working anymore. If I call the Backend of these extensions, I got a TYPO3\CMS\Core\Error\Exception:

PHP Warning: Undefined array key "selected" in C:\inetpub\wwwroot\typo3\sysext\fluid\Classes\ViewHelpers\Be\Menus\ActionMenuItemViewHelper.php line 116

In the log I got

Core: Exception handler (WEB): Uncaught TYPO3 Exception: #1476107295: PHP Warning: Undefined array key "selected" in C:\inetpub\wwwroot\typo3\sysext\fluid\Classes\ViewHelpers\Be\Menus\ActionMenuItemViewHelper.php line 116 | TYPO3\CMS\Core\Error\Exception thrown in file C:\inetpub\wwwroot\typo3\sysext\core\Classes\Error\ErrorHandler.php in line 145. Requested URL: https://test.url.de/typo3/module/tools/TeaserBeteaser?token=--AnonymizedToken--

I have absolute no idea, where the array key selected is coming from!

This has to be something to do with the update, because these extensions were working well.

I'm using Windows and IIS.

Has somebody any idea what has changed or how I can figure out the problem?

Answer 1

I created a bug report at forge for this issue as this is a bug in TYPO3 core.

With PHP8 an exceptions is triggered instead of a notice ([see docs])2.

There are quite a few places which still need to be fixed in TYPO3 Core and extensions. Therefore I propose to use PHP 7.4 and upgrade to PHP8 later.