TheSims crash when opening 'dowloads'

If The Sims 3 crashes when you open Downloads:
 Close the game and EA App.
 Go to Documents\Electronic Arts\
 Move the entire The Sims 3 folder to your Desktop (this backs it up).
 Start the game again — it will regenerate a clean, fresh folder.

If it opens fine afterward, your old folder had corrupted files.
You can then copy back your Saves or Mods folders one at a time to find what caused it.

Now it says that the entire TheSims3 is available only for Windows :(

Full Fix for The Sims 3 Crashing When Opening Downloads (Mac Version)

If The Sims 3 crashes when you open Downloads, or if afterward it says “The Sims 3 is only available for Windows,” follow these steps:

Close both The Sims 3 and the EA App completely.

Go to Documents → Electronic Arts and move the entire The Sims 3 folder to your Desktop. (This creates a backup.)

Start the game again. It will generate a clean, fresh Sims 3 folder.

Try opening Downloads again. If it now works, your old folder had corrupted files.

Copy back your Saves and Mods folders one at a time to find which caused the issue.

If you see the “only available for Windows” message after doing this, it’s a glitch where the EA App temporarily loses track of your Mac installation.

To fix that:

Quit both The Sims 3 Launcher and EA App again.

Reopen the EA App — it should automatically find your game.

If not, click the three dots (⋯) next to The Sims 3 in the EA App and select Locate Game, then point it to your installation folder (usually /Applications/The Sims 3.app).

Once it reconnects, launch the game again.

This method avoids reinstalling and usually clears both the crash and the launcher detection problem.