Re: The Sims 3 opens and closes without something happening and no error warning
@t0nai That's actually good news; the unknown error we understand and can usually fix (not always, but usually). Is there anything different about that new user account, like is one of them admin and the other not, or are the settings different? This is for my curiosity and future troubleshooting; feel free to leave the question alone.
In your case, with only the base game installed, you'll need to edit two .sgr files in TS3's program files to force the game to recognize your graphics card. Some iMacs come with dedicated graphics cards, and others don't. The specs you listed refer to an integrated card, but if you have both, the dedicated card might not have been listed in the initial specs. So please go to About This Mac again, then click System Report, then Graphics/Displays, and let me know which card(s) you see listed. Once I know which card you have, I can send you instructions for the edits, or a link to instructions if Bluebellflora has already prepared the text for your card.
Also, undo the edit you made to bypass the launcher. That can come later, if you want.
