Can't Run The Sims 3 After Installing Seasons Expansion Pack

At first, I click the play button on the launcher and goes into a black screen like it normally does, but right when the EA sign is supposed to appear, a window comes up with the "has stopped working" message. I used your Ultimate Fix, and now it doesn't even go into the black screen anymore. It just shows the "has stopped working" right away. I tried putting all the .exe files for Seasons in DEP, I tried backing up the folder Documents/Electronic Arts/The Sims 3 then deleting it, still didn't work. My other EPs are University and Island Paradise, and my version is 1.55

I was actually thinking of uninstalling everything and starting over again, but I posted here just in case I actually don't have to do that.

I also forgot to mention that I have Custom Content... at least I think I do. The Installed Content section of the launcher doesn't show any of the CC my sister got.