It is the world, which is probably bought off of the store. All store content is uninstalling itself every time you restart, so you have to re-download and reinstall it every time. But the site to re-download it from is breaking down too. You have to give up playing until its fixed. That means, only play 4 from now on. Or, only play Sunset Valley, and only CAS cc. Or, find your old disks and use them, vanilla, with the internet unplugged (off in wi-fi speak).
I wonder what the ratio to time is for how this is happening with 3 since 4 was launched, compared to how the Sims 2 was dismantled when 3 was launched. Pretty sure this is longer, so I suppose we have to be grateful about that ...
