I have been having the same problems. I cannot travel to prom. I hit the button "go to prom", and my teen didn't go. I am on my third generation and I have not been able to go to Prom in 3 months in real time (since I stopped playing my fifth generation of a different household). I even tried going to Prom after doing the "before prom" event, and still no Prom. My teen Sim does nothing and still no Prom. My teen Sim does homework, eat food, or do whatever and still no Prom. I have not been able to go to Prom at all. I even tried redecorating the Prom area and no luck there with getting back to Prom. I have no mods and I have been getting frustrated that Prom is not working. And yes, this is a every time problem of not being able to go to Prom. It almost seems like the game slides over the travel to Prom and the Prom event, but just keeps the game going without traveling and Prom is completely missed.