You said you installed GSX and the expansion, but you don't say if you activate them. They don't activate automatically on install, you must do it yourself.
In any case, as explained so many times on the forum and on the manual, you should never post questions about activation on the forum because, my next question would have been about your order and/or activation key, which cannot be answered in public. That's why you should always use email support for questions about orders and activation.
