Well I'm not an expert on this topic, but I think I know why this is happening. Well, there was a recent update for MPN on November 1st, due to this update, NEM is technically outdated, meaning that the game will not launch. I think it's best for you to just verify your game files and play vanilla MPN while waiting for v50 (I think?) to be released. I will try to respond to this thread when the new update comes out so you get a noti. Have a good day.