I've seen a couple of other posts on this same error, but they don't really answer the problem. I'm getting "PlayMakerUnity2DProxy requires the 'PlayMaker Unity 2D' Prefab in the Scene." I have the prefab in the scene. I only have the one scene and the prefab is there in the heirarchy and it's still there when I hit run. I took it out and put it back in again. I'm getting a lot of these errors, and I think they're associated with some objects that are getting created and destroyed, although I'm not aware of anything going wrong with any actual behaviours in the scene because of this.