My sister used the 'Send Sims to University' option to send three teenagers to Sim State. However, as soon as the sims arrived at the dorms, two of them were attacked by flies immediately after growing up into YAs. The third sim got out without any trouble and managed to plead for the life of one of them, but the other one was ignored.

University and Nightlife are both installed on the computer. I have already used the Nightlife patch.

So was this a bug, or just an unfortunate coincidence?

Do you have an old version of the Insimenator? I've heard having a pre-NL version of the hack causes exactly that problem. Try disabling it with the Clean Installer and updating to the new version (http://www.insimenator.net)

Aaah, that must be exactly it. I forgot to update the InSIMenator on her profile. Thank you!