One of the main appeals of the Sims 3, in comparison to its predecessors, is the ability for the entire community to age collectively. Except, not so much. I don't know if the good ol' "testingcheatsenabled" cheat tripped up my game, but nobody in my town ages. I have confirmed numerous times that aging is indeed turned on. I have reset my Sims and moved them in and out of different houses. I have messed around with different lifespans. Nothing works. My Sims' aging bars are stagnant. I can only manually usher them into the next life phase through cheats.
I recognize that Twallan's Story Progression Mod will take care of the aging problem, but I'm hesitant to download it. My game has crashed in the past, and I hate to screw around with it by introducing foreign mods. I'd appreciate any thoughts on how to address this aging issue without having to resort to downloads.
You may not be using Twallan's SP, but are you using any other mods? If so, remove them. Does it still happen? If not, one or more of them is outdated and is causing conflicts.