Sims 3 on my Mac doesn't work...

MaurineLejol  Please list the full specs of your Mac: everything under About This Mac including the OS and except for the serial number.

Please also let me know what expansions you have installed and what world(s) you're playing in.

Hello, 

So about my Mac : 

Processor : 2 GHz Intel Core i5 quad-core / Graphics : Intel Iris Plus Graphics 1536 Mb / Memory : 16GB 3733 MHz LPDDR4X / Storage : 500 GB  / MacOS : Sequoia 15.0

And I have installed the pets expansion pack and I play in the Appaloosa Plains world. 

MaurineLejol  This particular model Mac used to have some unusual problems with Sims 3, although I haven't seen any reports recently.  So this could be at least in part tied to Sequoia rather than intrinsic to the Mac.  If you have the ability to revert without erasing your data (I don't remember how the betas work), it could be a worthwhile experiment.

Otherwise, please try playing a new save in Sunset Valley, without Pets installed.  Open the "The Sims 3 Packs" folder, which will be wherever you installed the game, likely one of these locations:

Users > your username > Applications
Applications > EA Games

and drag the EP05 folder to the desktop.  This will effectively uninstall Pets; to add it back, restore the folder.  You'll also need to move or rename the Sims 3 folder in Documents > Electronic Arts since it will have been exposed to the Pets EP, so to speak.  Doing either one will remove your saves and other user data, but it'll be intact and can be restored later.

Point is, let me know how a new save runs in Sunset Valley and we can go from there.

Even when I play in the Sunset Valley world, apparently it doesn't work too. Then I followed the instructions about the Pets EP, start a new game in Appaloosa plains world and after 5 minutes of game, it closes all of sudden and my computer asks me to restart it every time with the message “your session has expired”.

MaurineLejol  If you uninstalled the Pets expansion, you wouldn't be able to start a new save in Appaloosa Plains—the world would be unavailable.

I don't recognize the error message you're getting, so could you please post a screenshot?  Unless it's from the EA App, in which case try putting it in offline mode before launching Sims 3.  The option will be in the menu bar in the upper-left corner of the screen, under Account.

I kinda had the same Problems on my Mac. For me I started the Game and spent like 5 Minutes in game before it just closed itself. I don't know how I found out but for me it kinda works if I open the game and load into my save file and then cut off the internet connection. It still randomly crashes sometimes but at least I am able to play for more than 5 Minutes (I play around 2 hours a piece with this trick BUT I have to remember to save like every 10 minutes so my progress doesn't get lost)

MaurineLejol  Did you also move the Sims 3 folder out of Documents > Electronic Arts?  If not, please do that now.  And just to clarify, does the game work or not, and if so, how is performance?

If you can't play or are still getting crashes, please let me know how much free storage you have (About This Mac > Storage) and whether iCloud Drive is active and syncing the contents of Documents.  I don't have Sequoia installed, but the setting should be somewhere like System Preferences > Appld ID > iCloud Drive > Options.

Yes I also moved the sims 3 folder, the game is working very well for 20 minutes and then the screen starts to freeze and flash and I'm still forced to quit the game. About my storage I have 314 GB free on my laptop and iCloud is activate for the documents but I still have a lot of storage on iCloud also.