The floor is ocean.

Inside of housing and shops/ruins/caves are recognized as outer seas, so I could not drop things or install structures on the floor of housing.

In shops also clouds of outer seas come out and cannot drop things on the floor. The shopkeeper doesn't fill up the fridge, and when I pick up things with spacebar key in the fridge, my game crashes. In ruins same things happen.

So I could not drop lanterns on the floor for turther works like hacking/shearing vines off the gateway.

One more point = bats and plant monstrosities grow up so fast.