Game not recognizing some of my expansion and stuff packs

[Motoki]

All of the sudden yesterday when I started the game instead of loading with the 70s, 80s and 90s Stuff loading screen the game started loading with the Showtime screen. When I got in the game everything relating to the Diesel Stuff Pack, Katy Perry Sweet Treats Stuff Pack, Supernatural expansion, Seasons expansion and the 70s, 80s and 90s Stuff Pack is gone even though I own those packs.

In the launcher the icons for those packs are showing sort of faded and greyed out indicating the game thinks I don't own them. If I mouse over them it says 'Requires <pack>' but of course I do own them and have them installed.

See the image: http://img171.imageshack.us/img171/4893/simsdlcproblem.jpg

I've tried logging out of my sims account in the launcher, I verified the game cache in Steam several times, I temporary moved out the entire folder C:\Users\MichaelO64\Documents\Electronic Arts\The Sims 3 to try running the game at fresh default settings with no saves or custom content, in desperation I uninstalled and reinstalled THE ENTIRE GAME (all 22+ GB!) but I still cannot seem to solve this problem.

I would just give up and switch over to Origin but I don't have a key for my 70s, 80s and 90s Stuff Pack so I can't do that either. :-/

[WeHaveNoMouth]

I also have the same problem but I just have seasons missing :-(

[Motoki]

Someone in the other thread posted that you can try manually adding the key for it to the registry. See here: http://steamcommunity.com/app/47890/discussions/0/846943514108133718/#c846943514110410442

I'm at work at the moment but I will give it a shot when I get home.

*Edited to add: Of course I don't actually HAVE the key for the 70s, 80s and 90s Stuff pack, but that's a whole other issue...

[thx1111]

Created a guide, hopefully it helps, out sick today from work, so had some "free time"
http://steamcommunity.com/app/47890/discussions/0/846943514132091361/