No Element/Plugin-selection + Error on edit (Typo3 12)

[LautundKlar]

The Slider-Elements on the current Typo3 12 Version is not working properly.

Problems:
I cannot create a new Slider-Content-Element (no Option even after enabling every PageTS).
When i try to edit the demo-slider-elements i only get the following error:

PHP Warning: Undefined array key "type" in /var/www/vhosts/lautundklar.dev/testtypo3.lautundklar.dev/vendor/fluidtypo3/flux/Classes/Builder/FlexFormBuilder.php line 80

Steps to reproduce:

1. Download latest Typo3 12 Demo
2. Import database and install via composer
3. Open backend -> Edit slider-elements on page "ws_slider" -> Error follows and no options to add a new slider.

[GCO-MR]

Same here.

TYPO3 12.4.23 composer-installation
ws-slider 12.1.4
flux 10.0.10
PHP 8.2 (also tested with 8.3)

(1/1) #1476107295 TYPO3\CMS\Core\Error\Exception

PHP Warning: Undefined array key "type" in /var/www/clients/client137/web402/web/vendor/fluidtypo3/flux/Classes/Builder/FlexFormBuilder.php line 80
in /var/www/clients/client137/web402/web/vendor/typo3/cms-core/Classes/Error/ErrorHandler.php line 141

        }

        $message = self::ERROR_LEVEL_LABELS[$errorLevel] . ': ' . $errorMessage . ' in ' . $errorFile . ' line ' . $errorLine;
        if ($errorLevel & $this->exceptionalErrors) {
            throw new Exception($message, 1476107295);
        }

        $message = $this->getFormattedLogMessage($message);

at TYPO3\CMS\Core\Error\ErrorHandler->handleError()

in /var/www/clients/client137/web402/web/vendor/fluidtypo3/flux/Classes/Builder/FlexFormBuilder.php line 80

    }

    public function parseDataStructureByIdentifier(array $identifier): array
    {
        if ($identifier['type'] !== 'flux') {
            return [];
        }
        $record = $identifier['record'];
        if (!$record) {

at FluidTYPO3\Flux\Builder\FlexFormBuilder->parseDataStructureByIdentifier()

in /var/www/clients/client137/web402/web/vendor/fluidtypo3/flux/Classes/Integration/Event/BeforeFlexFormDataStructureParsedEventListener.php line 21

    public function applyFluxFlexFormDataStructure(BeforeFlexFormDataStructureParsedEvent $event): void
    {
        /** @var FlexFormBuilder $flexFormBuilder */
        $flexFormBuilder = GeneralUtility::makeInstance(FlexFormBuilder::class);
        $structure = $flexFormBuilder->parseDataStructureByIdentifier($event->getIdentifier());
        if (!empty($structure)) {
            $event->setDataStructure($structure);
        }
    }