You can find the files and folders for the game in:
--->Documents > Electronic Arts > Sims 4
You'll be wanting to look for the files and folders below. The other files and folders not mentioned here will auto-regenerate.
Options.ini File -- The graphic/sounds/gameplay options
Saves -- Saved game files - leave out slot_00000001.save which is the autosave. It is not used anymore.
Tray -- Sims, Houses, Rooms and Community lots
Screenshots -- Photos you've taken with the C key in-game.
Recorded Videos -- Video clips you've taken with the V key in-game.
Mods -- Game mods and Custom content like clothing, hair, skins, and makeup
** Put mods back one by one to make sure they all still work.
Again, please do test your mods and custom content as they can become outdated with most new game patches.
How to Fix Problems with Mods/CC
http://www.carls-sims-4-guide.com/forum/index.php?topic=25031.msg426156#msg426156Or just save your Sims 4 Folder to your desktop, and rename it current or something like that. Go into Origin, right click on Sims 4 and select play game. This will create a new folder. Then copy back the files and folders listed above so you can have access to any saves, families, houses or rooms you want to play with.