This is more human error but is possible to accidentally do.
If you have a an object that is supporter set to be placed On Object and you have accidentally chosen the same object to be placed on, runner will crash.
Perhaps an prompt could tell user the error? then they click on apply ie. You cannot put an object on itself. In most cases this is fairly obvious. But sometimes by mistake the wrong object can be chosen.
Object set to be placed on itself causes runner to crash
