The problem probably reaches to the objects in the game too, but I haven't tried to play.

So I literally moved my Sims 4 files and folders from my laptop to my boyfriends computer, to avoid all the installing etc. work.
The game should run smoothly since his computer is way more suitable for gaming than mine, the specs meet requirements.
The game does work normally, but the sim in the cas mode looks like a patterned doll. Oh yeah, and the background's black.

I've tried cleaning up unnecessary cache files. I've tried removing all the mods and cc. Nothing works. I think the problem's with the computer??

Here's an example pic:
http://postimg.org/image/53d2u3evf/full/

So, what the heck?! Help anybody?

I think it's because you moved the files to his computer without properly installing it. It's just a wild guess, so I don't know if that's the correct reason or not.

Try reinstalling the game, and see if it works. Good luck!

It's Ronald McDonald!

Yep I would try reinstalling and then add all your game saves tray folder etc: