You know that bug that you get with large projects / randomly generated stuff? It's a glitch where inside of the editor you can see all of your stuff that was in game and some things are even MOVING in the editor?
To solve this it's so simple =D Just put a key down event on everything that has the glitch effect, make it "esc" and do "Delete Actor - Event Actor" Problem solved, now when you press ESC to return to the editor it wont bug! =D