but as i said before - i installed a paid version ....... what is this??!!
There's no "paid version". There's only one version of the scenery available, and it's the Trail. So, you can't have installed a paid version, because there's no such thing as a paid version.
Of course, since you bought the product, you also got a purchase receipt with your Serial Number so, by registering your Serial Number, the Trial will become a Full version.
So, you simply need to select "Register Serial" from the Addon Manager, insert your Serial Number and let it activate.