Error with University. [SOLVED]

Hello,

I downloaded and installed The Sims 3 University, like I did with all other expansions. I cannot get it to work, since I get this error:

Je hebt blijkbaar een onofficiële gamebewerking uitgevoerd die niet overeen komt met je huidige versie van De Sims 3.
We raden aan om deze gamebewerking te verwijderen, of een recentere versie van de bewerking uit te voeren.
Als je dit niet doet, kan de game crashen, of je kunt te maken krijgen met verschillende bugs.

I followed the steps in the installation guide and updated with the manual patch and used the ultimate fix, but this still results in this error. Can you tell me what I can do or try to solve this?

Thanks a lot in advance!

//EDIT

Solved already. In case someone has the same problem: it had to do with
installed mods. After removing them, the problem was gone.

I couldn't read the German and Google wouldn't translate it for me for some reason. So I'm glad you figured it out.

(Is the error saying, basically, that you've got an unofficial modification that doesn't match your game version?)

Hello,

Sorry for the late reply!
Enjoy the game and let us know if you need more help!