Sims 3 Won't Launch after launcher - MAC

@Jess__Web03  Please try launching the game in windowed mode.  Go into Documents > Electronic Arts > The Sims 3, open Options.ini, search for fullscreen , and set it to 0 (zero).

If that doesn't help, please move the entire Sims 3 folder out of Documents > Electronic Arts and onto your desktop, then try again.  This will remove, but not delete, all your saves and other game data, which is fine for the purposes of this test.  This will also reset the in-game options, so edit Options.ini to force windowed mode again if the game won't launch the first time in the new folder.

Hi! this same problem happen to me and when I move the sims 3 folder it worked. What do I do? I dont want to lose my saves or costume content ☹️

@Constanza649  The problem is something in your old folder, probably not the saves.  So test your custom content first.  This article may help:

https://sims3.crinrict.com/en/2011/01/tutorial-how-to-get-rid-of-unwanted-custom-content.html

For the other content you want to keep, test it a little at a time in the new folder.  The game will regenerate some files and folders, making the old versions redundant; in those cases, just use the new ones.  Here's a description of everything in the user folder so you know what you might want to preserve:

https://sims3.crinrict.com/en/2011/01/faq-user-files.html

Hi, I was experiencing this as well. Try this, go into documents>Electronic Arts>Sims 3. Make sure all the files are downloaded and not sitting in the cloud only. Mine launched no problem after I had downloaded the files back onto my Mac. 
further more, you can opt to keep them downloaded to avoid this happening again.