This site is being deprecated.
Please see the official X‑Plane Support page for help.
For the X-Plane 11 Digital Download from here you have one product key and access to the X-Plane 10 digital download. You can use only one version at a time (10 or 11). You could have some problems with your digital download authorization when running on multiple computers at the same time. Your product key can be even locked.
This site is no longer being actively maintained.