I built an arena in my home, but due to space limitations I had to build it out over water. I have the large planks as a flooring and some AOE spells just go straight through it to the bottom of the water while others won't allow me to cast at all and say "Invalid Location." I have also tried platforms, Stone, and even tried turning a hedge on it's side as the floor, but they behave the same way. Is there a furniture item that can be used successfully as a suspended floor or is this something that still needs to be fixed? If I can walk on the items, I should be able to cast my spells on them.