So Resources.Load what on earth did you guys do there. If I load a prefab in a MB awake, it places it in the scene. Yes you are reading that correctly, so instantiate then of course creates a duplicate in the scene. Resoures.Load also sporadically returns null when called in RuntimeInitializeLoadType.BeforeSceneLoad. So my first post above about case sensitivity, that wasn't the problem. My first scene load just happened to return null on the one prefab with bad case. Something impacting rewired changed also. It's causing massive waits that show up in the profiler as rendering waiting, because the real culprit whatever it is isn't being logged. Now if disable rewired and manage to load without hitting any null resources, performance actually looks to have improved.