I recently got Pets and now some of my pets and some of my Sims, even though I have aging enabled, say that they "never" age. But it's not affecting all pets or all Sims in the household. And if I try to age them (using a cake), they don't show up in the list. I can age them using testingcheatsenabled, but they still don't start aging after that.
I do have some NRAAS mods, but they are all up to date.
I tried looking for threads about this, but each one seemed to refer back to the Sims3 site (which doesn't exist) and so I get a message that the page can't be found "even under the bed."