TYPO3 Core

When using the newly introduced Event `AfterTemplatesHaveBeenDeterminedEvent` to skip sys_template records, the Forms Module throws an exception.
We use the bolt extension (https://github.com/b13/bolt) to make integrators life more easy and put all ts-templates under version control.

The module throws the following exception

TYPO3\CMS\Form\Controller\AbstractBackendController::resolveResourcePaths(): Argument #1 ($resourcePaths) must be of type array, null given, called in /var/www/html/vendor/typo3/cms-form/Classes/Controller/FormManagerController.php on line 80

This exception is thrown when no Typoscript template (in this case the extensions "yamlConfigurations" settings) is found.

After some debugging I would guess, that this is somehow caused by the extbase module.
The requests site-attribute is of Type "NullSite". The typoscript is fetched by SysTemplateRepository->getSysTemplateRowsByRootline()

The requests site attribute of Typoscript Module is of type "Site" - there everything is fine.
The typoscript in this case is fetched by SysTemplateRepository->getSysTemplateRowsByRootlineWithUidOverride()

Both getters respects the event at the end, so the error must occur earlier.