I played Sims on my Mac Book air absolutely fine until the Big Sur update where every time I clicked on play on Origin the launcher would never appear but an error message "sims 3 unexpectedly quit popped up. I tried uninstalling and reinstalling both sims and origin but to no success, I spoke to an EA advisor and they suggested a long list of things, and the only one that seemed to work was creating a guest user on my mac and installing sims from that user and playing it from there also, all works hunky-dory now.
My next issue that someone might have an answer for: I can download content from the sims store to my launcher fine however if I try and install it works 1 out of 20 times - I open, close, open, close the launcher, and then finally it installs (very strange). Any advice?
@MauriceSim The launcher has always been finicky, and in some ways it seems even more so now: content that used to install sometimes does not, for no apparent reason. Are you installing EA-made Store content, items uploaded to the Exchange, or content hosted on third-party sites? Do the same items not install at first and work later, or can you install everything eventually if you keep trying?
If you'd like to play in your current user account, please also check whether iCloud reset itself to automatically sync the contents of Documents with cloud storage. The settings often change with OS updates, and iCloud trying to sync could interfere with your ability to run the game. This guide was written for a different issue, but the relevant settings are the same: