Do you get the message when you start a certain save game or when you start the game itself or is it when you start the launcher ?
When did you clean the registery ? Before or after you uninstalled world adventures ? Did you also uninstall the base game ?
Also try the factory reset described in this post: http://answers.ea.com/t5/The-Sims-3/FAQ-Troubleshooting-Steps/td-p/714/
I get the message when I want to start the launcher. I cleaned it today and uninstall world adventures afterwards. No I didn't uninstall the basegame because I couldn't find the CD.....
Try bypassing the launcher as described here: http://answers.ea.com/t5/The-Sims-3/FAQ-Troubleshooting-Steps/td-p/714/
This is just for testing purposes to see if the game itself works.
If that doesn't start either, uninstall WA again, THEN clean out the registery not the other way round. Also try the factory reset linked in the post before.
