Re: Roommates?
Hi @drcwosly :D I'm the same as you on this. I usually play a single Sim (with one or two pets) but I love having other NPC Sims around so I bought the Discover University pack largely just for the roommate game-play feature. I've tried advertising for a roommate with several of my Sim households, in different saves, different worlds, both with and without mods, and like you I have never had a single Potential Roommate respond to any of my ads. I know it works fine for others and I have yet to figure out why it won't work for me. I am Me Too with this thread.
My solution has been to directly ask NPC Sims I wish to add as a roommate. If they meet the conditions of being in a single-Sim household and are currently homeless they will say yes and become your roommate (edit: you might also have to be currently advertising for a roommate for the Ask to be Roommate dialog option to show up). This works fine for me every time. At first I was still somewhat disappointed that the advertising for a roommate feature was not working, but the more I think about it the more I realize I would rather have an NPC townie friend as a roommate than a total stranger anyway. At least an acquaintance with preferable traits.
You might want to consider giving that a try. You could always directly ask an NPC Sim to gain one roommate and still leave the ad open to see if you can ever add a second roommate that way. You can start to enjoy the roommate game-play features while you continue to try to make the other part work. I love having roommates for the variety and randomness they add to my game. Btw- You might also wish to consider adding the Cats and Dogs EP for the same reason. Pets make awesome roommates! I think Cats & Dogs and Seasons are still my favorites :D
Good luck, I hope this helps!
P.S. I am hoping some other Simmer will add a post here with a solution that will help both of us! ;-D