I haven't played Sims 3 in a while but I did have a similar glitch. The problem for me was that I had placed an apartment that I had renovated in a previous game. A bookcase in the apartment had books written by my sim in that previous game. When I started a new game with the same sim (same name) she could not complete writing some books. It was because she already had books with the same title by the same author (her) in the game because of the books in the bookcase so she would glitch out on finishing a novel. Not sure if this is your issue but sounds similar.