So I was at Core city when I decided to sneak kill a guy inside a hidden room where nobody could see, once I got out everyone was neutral around me so I saved my game and after the quest I was doing I tried to get back to some vendor NPC to sell my loot when everybody started attacking me.... I tried to sneak past everyone to complete my quest and keep playing on that save but it is just impossible.... My save is broken now and there's no way to remove the threat level..... This game is broken, I wasted so much time on it. There should be a way to remove the NPC aggro when it is game breaking.