Sims 3 starting problem.

JoshuaSims0

so, i just got the sims 3. (I have the sims 4 already) and whenever the try to play it it says "Download in progress" and a full download bar. so when i play it lags. when i play the sims 4 it is totally fine. (I AM ON MAC)

igazor

Ugh. Please know first that unlike TS4, which was done properly, TS3 for Mac is a mess. No matter which model Mac you have, no matter how much RAM, the game can only utilize 2 GB and that's it -- if it reaches for more along the way, it will glitch up the graphics, crash, and/or Error 12 when trying to save -- or not even start. It's the only iteration in this series that EA did this to and they never went back to make a proper port of TS3 into the Mac OS like the others are.

But, sounds more like you are having a different kind of issue. The Mac specific board is actually over here, and you will find several Read This First and Mac Users Guide type of threads there for TS3 players. It's not an entire disaster for everyone who plays it, it's just not going to carry a complete, all EPs, long running multi-generational game very well for many players.
http://forums.thesims.com/en_US/categories/mac-discussions

You might want to open up a new thread over there, now that you can, and list out your Mac's specs from About This Mac on the Apple menu (year and model, processor, RAM, graphics card) to see if the others can get you past where you are now and offer some advice. Sounds like an Origin related issue if it's repeatedly stuck on downloading, even though apparently you can still get the game launched in the meantime.

And, by the way, it sounds like you are using Origin to start the game? Mac players don't have to do that, so a shortcut to the TS3 executable might help (a little).