That error means you are trying to delete something that doesnt exist, first of all check if you referenced it correctly (Wrong location or maybe a typo are the most common)
If the code is "correct", then check if that node is not being deleted before by something else.
Still, it seems like we're missing a lot of code to reach the cause... For example, where does this "area" var come from in the
By the way, to avoid problems, the player's root node should be a
RigidBody not an