I had this same problem. Because I have had so many saves get corrupted or bugged, every day that I play I make a new save. That way I can go backwards until I find a game that is not bugged. This problem happened for me on a save wherein I installed subways to Moonlight Falls. Also that day, I used the testing cheat enablelotlocking. Those where the only odd things I did, so maybe they were the cause. My advice, make lots of new saves.
