Sims 3 crash after loading

I got the Sims 3 with the expansion pack Ambitions before (what worked correctly), but then because the internet of that computer didn't work, the whole computer had to be again installed, so my Sims 3 game had to be unïnstalled. When the computer was working again, I installed exactly the same as before, the same files of The Sims 3 and Ambitions. So I started it after it was cracked and installed and everything worked fine until the loading screen. When the loading bar was full, the game crashed and closed. Also after a few tries, it still every time crashed.

Now it is solved because I uninstalled The Sims 3 and Ambitions and installed again The Sims 3 and not Ambitions, and some other expansions and applied the ultimate fix. Now it is working fine and it doesn't crash.

Does somebody know what happened and why it crashed, because it worked at first? I know it is solved by now, but I would like to know what happened ^^

Admin edit: Topic moved to right section.

- ADMIN