Get To Work > Get Together > City Living > Update v1./Vampires > Parenthood > Fitness Stuff > Toddlers Stuff > "Error Code 3" fix (link at bottom of guide)
Another window will pop-up telling you to choose the executable, select “/Program Files/Electronic Arts/The Sims 4/Game/Bin/TS4.exe”, and close the wrapper. When it has finished, un-tick the “Launch the Sims 4” box because it won’t work, then then select “Finish”. Select “The_Sims_4_Setup.exe”, and wait till an installation window pops up. Locate The Sims 4 base game folder that you extracted with Stuffit Expander.
Then select, "View wrapper in Finder" and drag the application to your desktop. If "Mono" and "Gecko" pop-ups appear, click install.
Open the downloaded "Wineskin Winery" app and install and engine by clicking "+", scroll down to wrapper 2.6, click "Download and Install", then "OK".The Sims 4 and all expansions (using the magnet links) from (there should be 8 including the base game).
(If you had already downloaded Wineskin to try and install the game, I suggest uninstalling it and restarting-unless you use it for other apps.)
This is my version of the guide for those who get errors along the way or don't know how to begin.