What happened to my sim's celebrity - all taken away

I have a sim who is a painter, and that is who she is gaining her celebrity status. She is not doing anything else but painting and finally got to her first-star level. Then all of a sudden the game put her back to zero and says she has not been spending enough time with the public. This happened right after she sold another of her paintings (the option to gain fame). Why did the game take it all away, not just a small amount, but all?