Hello there! I've been playing Sims 3 for a month approximately (not the first time I play the game though). I bought the main game with the following expansions: World Adventures, Ambitions, Generations, Late Nite and Seasons, and the High-Tech Stuff content.

I borrowed the Sims 3 Pets expansion from a friend and I installed it, but the game got buggy and I got tired so I uninstalled it. Then I tried to play again and the game crashes when my game is loading (the picture of my family in the main menu still has a cat that I adopted in game).

My sister can still play the game with her family and she doesn't have problems at all.

I have cleared the cache files and thumbnails and used CCleaner, I don't know what else to do.

Please help, I don't want to lose everything in my main file. ):

From the sound of it, you played this ongoing game and saved it while Pets was in place? Many of the EPs cannot be removed from ongoing games without making them unplayable, I am certain that Pets is one of them. There are sims (cats and other animals) in this saved game file that are now undefined, there are skills, careers, traits, potentially lots present that are dependent on the EP being there also. There is likely no solution here other than reverting to an older save from before the EP was first added if such a save exists, purchasing and installing Pets again, or starting up a new game.