Platformer won't load

My platformer won’t load in preview mode. I don’t know why.

If a project doesn’t load or looks frozen it’s almost always an infinite loop. Your while event doesn’t have any conditions. So, it never exits it. It’s probably not the best approach. Tweens have various conditions and you might want to use a Boolean variable to disable events or disable a behavior until a tween has finished. If that is your intention.

Even with a condition the while event would keep looping and replace / restart the tween.