Sims randomly age after loading into Live Mode
This bug was fixed in Patch 1.90.375. Be aware that you still can be hit by an change in age initially as Maxis changed the length of the livespans
[Mac] Endless loading screen when trying to load a savegame
This bug was fixed in Patch 1.69.57/ 1.35
Game freezes on Loading Screen
This particular issue was fixed.
Game hangs on loading
Long or endless loading screens can have multiple causes and depend on where they occur.