OpenBuildings Designer Update 6 - Floor Manager Defaults to a 'None' Floor

Hopefully someone can clarify what I am missing in my setup of Floor Manager.

The two appended screenshots illustrate the issue.

When trying to select a floor in Floor Manager 'Set Active Floor' dropdown  there is always a 'None' floor inserted below the 'Site' level in the dropdown hierarchy that prevents me from selecting a floor level below the "Building' level where it should rightfully be.

This 'None' floor is nowhere to be found in the Floor Manager setup toolbox.

Please help. I know I'm missing something.PDFPDF