I remember getting a similar message when I tried to load the game from the launcher when my Internet connection was down. But in that case my game would NOT load.
I ALWAYS refuse to allow the game to connect to the internets, so that's not a variable in my case. The error just popped up two days ago when I tried to install a package. That's not bothering me as much as getting rid of the damn things all together. By things I mean Sims3packs and by damn I mean motherfuckingcocksuckingpaininmyass things. This is how angry and frustrated I am at the bastard who came up with them and the launcher, and the horse he rode in on.