WSOD ($form_state) must be of type FormStateInterface, Drupal\Core\Form\FormState given

I have added a patch to fix the issue.

Thanks, I could see the issue myself:

I applied the change and I don't see the WSOD anymore:

@danrod, i changed it back to RTBC.

The maintainers usually mark it fixed once the patch is accepted by them and applied to the code base

Doh, you are a maintainer, @danrod. Sorry for my confusion.

Automatically closed - issue fixed for 2 weeks with no activity.