Game crashes after long loading time

For about three days, my game has been randomly crashing throughout the day. At first, I thought it was a problem on my part. To explain, I am playing off of a external hard drive connected to a monitor, and I also do use CC and mods, but I've never ever had this problem until August 3rd, where it will just randomly crash. At first, it was if I played for more than six hours, and I would make sure to excessively save. But now, as soon as my game loads in, which it takes a long time to load in, after just two or three minutes of playing, it will crash. More specifically, recently, it has crashed immediately after I hit the "buy restaurant" button under household on the computer. Then the EA app will just hop up and down after the game closes.