[Fixed] Can't get married even though engagement

I've had my sim be in a relationship for over a week. She's proposed to a guy, and they are now fiance's, and it says that in the game. I've advanced the relationship to the highest it will go, yet it won't let them get married. I have the arch, and the other two things needed, but it says that my sims are not engaged but when I click on the dude it says they are. I'm so confused, on why it won't let me?