I know there must be a simple answer. Residential: I have tried to install a tub on the lower level but it attaches to an associated level BF below (how to change this)? The level constraint is greyed out. Other fixtures insert correctly from the library at the correct level and they are not greyed out only the tubs. I think I have two issues why is the level contraint greyed out in the properties and where do you modify associated levels? I have tried everything I can think of. I'm still a novice trying to learn. JD