If you don't see the buildings, but you do see the Addon Manager, there's NOTHING wrong with Addon Manger, there's nothing wrong about having installed a wrong version, there's nothing wrong with Cloud9 products. If there was, you'd either had a clear message asking to update, or (in some cases were your version was *really* old, a crash)
The scenery might fail to appear also for reasons totally independent from Addon Manager or activation. Remember: if there's a problem with registration or activation, the scenery will NOT disappear. It will go in Trial mode, meaning it will disappear after 5 minutes but, before that, it will run fine.
Some reasons why the scenery might disappear at start.
- A double entry for Zurich in the SCENERY.CFG file. A double entry surely will make the scenery disappear.
- A missing BGL. Have you tried to simply reinstall it, without uninstalling first ?
- A SCENERY.CFG that contained illegal commands or hand-edited lines with illegal names or keywords. This might confuse the installer, that can't figure out about area list, if there's something wrong with the SCENERY.CFG, thus not being able to add it.
Please check Zurich it's in the Scenery Library. If not, just add it manually. There are two areas to be added: Zurich and Zurich Terrain. Terrain should be lower than Zurich and both should be, ideally, on top of everything else.
However, I need you to be more precise about what you meant by saying the the scenery disappears: does it disappear after some minutes, like the Trial, or it simply doesn't show up right from the start ? In this case, did it work before, when it was in Trial ?