https://s2.postimg.org/hdodzbq5l/SSS.png
Double clicking inside the corridor created a floor that goes through anything that's enclosed, even if it's meant to be open air.

It reminds me the third deck of the USS Defiant (form, rooms, main accesses (in red lines), ...) [:)]



More seriously, did you verify all heights for each wall of courtyard ?

And the parameters of each level ?

=> little tip : in first time, I give a different color for each nearer walls to see an eventual error.

[:)]