(Deleted by user)

In my experience those messages the OP mentions are newer over the last few years. I had uninstalled in 2017 (and Origin) reinstalled last year to check out game again, and couldn't play without being online, first, and none of my packs were available unless I went online. ETA: And yes, I didn't have access to my own library of homes and Sims until I went online though I have the saves and they were in my saves. Needless to say that was enough to make me not play for another four or five years.