I am new to CA and still very much into the learning phase but ran into an issue that I just cant solve. While working in terrain mode, I drew up a deck using the railing tool and the deck was created successfully. However when I did a section view it showed that new walls were created on my second floor. I went back to default the default set and sure enough new additions were added to the second floor. I am not sure how this happened. Deleting the deck removes the added info. Can someone advise me on my error?