This has happened to me a few times when I play the dorms in the university. Usually for me when this occurred it was on a roommate that was suddenly tagged as a neighbor. This time, however, it's on my sim who just came back to the campus housing from her morning class. Now she can't enter the house to do her homework.
For me, this first happened before this most recent update. I didn't bother trying other things because the affected sims were roommates tagged as neighbors but now I need to try other things since the affected sim is the one I'm currently playing. I can't move her out and back in because she lives in campus housing.
Update: So I just had the male sim who I'm playing with her at the university invite her into the house and her options reappeared, but she was still tagged as a neighbor. After the options reappeared, I removed her from the household and added her back to the household and she's back to being playable again.
I hope this can help others who run into this while playing in the dorms or the campus housing.
