I have to say this is the worst version of the engine I have ever used and I’ve been using unreal since udk days. its so badly broken. it keeps changing my anim montages. doesn’t save my work. and to top it all of play in new editor window is totally broken, after a couple of seconds it starts slowing down, and then becomes totally unplayable. and it’s not my code, it’s yours. I know it’s your code, because it runs perfectly in standalone game. I never had this problem before. as far as i’m concerned 4.12 was the best engine version you released, everything ran perfectly, I would switch back to that version if I could but my project has been updated, which means i’m stuck with this version.
I am closing this question as a duplicate of Play in New Editor Window Runs Slowly - Programming & Scripting - Unreal Engine Forums
Please move the discussion to that thread.
Have a great day