The Sims 3: University Life - Sims won't/can't attend class anymore! How do I fix this??

I have two sims enrolled in the university. One is studying art and the other is studying science. They do not have classes in the same building. Two separate buildings, two separate schedules. I was able to move my sims in problem-free. I can see both of their schedules and they attended their classes on the first day. However, on the second day, I got the notification that one of their classes would start soon, so I tried making her go, but she was unable to. Not matter what time I tried (after recieving the notificaiton, as soon as class started, 5 minutes after class started, etc.) she was unable to go. It repeatedly told me that she did not have class at the time even though she clearly did. Then the exact same thing happened with my other sim when it was time for her class to start. I haven't reset my sim and I don't use any mods. I've cleared my cache as well and it is still doing this, so I'm not quite sure what the problem is. Somebody please help me solve this!!! 😕mileysad: Any and all help will be GREATLY appreciated!

~Thank You!!!