Second story floor queued before first story walls

My hearthlings are trying to build the second story floor before the walls of the first story.


Save file: https://drive.google.com/open?id=1NwfLP5xtpgLzGglvfo8De2zc9r1q7NfL

Did you use the slab tool on the second floor?

Nope, used the room tool. Only time i used slabs was on a few parts of the roof.