Reflected Ceiling Plan 3D document in Archicad 20

[Anonymous]

I am trying to make a reflected ceiling plan in archicad 20 with the Floor Plan Projection option in a 3D document.
It is greyed out.
Am I doing something wrong?
Or is there another way I should be going about doing this now?

[Anonymous]

I figured it out ~
I needed to be saving the 3D document from the Floor Plan window, NOT the 3D window.