Checkered terrain entities can cause a corrupt level if there are no other objects

[city41]

this level

does this at run time

if you add just about any object, say one coin, then everything is fine again.

My hunch is this is a bug in sma4. But not sure it's worth worrying about, as who would make an empty bonus room? But possibly could warn them if they do.

[city41]

If you create a "complete" room with floor, two walls and both lower corners, the game no longer crashes