Okey, after finishing all quests which involve the Salvatores I finally wanted to go through with the assassination of Louis. The problem is just that nothing happens. My character can't even talk him nor does he go hostile once I fail a steal attempt. This has happened to couple of other NPCs (black vault citizen gate guard, slaver guard NCR). This bug has never occurred to me in my previous games. Anyone knows if there maybe is a way of fixing this?