Hello everyone, I've just discovered this amazing software and find it really easy to use but I cannot solve this:

I have an "L" shape stair with 3 steps straight and the Others to the left; over the first steps there is a ceiling (that is the first level floor!) but the software creates a hole over the Whole stair so on the first floor I have a hole in my bedroom [:))]

is there a solution? could not find a way to "cover" the hole with the floor

Thank you.