TYPO3 Core

When adding v10 compatibility to an Extbase extension, I'm currently struggling with the following error message:

Cannot create empty instance of the class "TYPO3\CMS\Extbase\Persistence\ObjectStorage" because it does not implement the TYPO3\CMS\Extbase\DomainObject\DomainObjectInterface.

The error occurs in the current TYPO3 master, as soon as getters/setters for ObjectStorage properties are added to a domain model. I tried several different annotations for the ObjectStorage property, but all result in different error messages (mostly in relation to ObjectStorage as shown in the example below)

"\TYPO3\CMS\Extbase\Persistence\ObjectStorage<\TYPO3\CMS\Extbase\Domain\Model\Category>" is not a valid Fqsen.

I created a very simple test extension to reproduce the problem: https://github.com/derhansen/extbase_test

• Install extension
• Create a record of type "test" on a page (Add title and select at least one category)
• Add plugin to page and select storage page where record was created
• Error message is shown in FE when page with plugin is called