Hi Umberto,
Sorry to piggy back this post, but today I was provided with the same message. I was trying to get to grips with GSX jetways etc, in P3Dv4.5 and I must have done some thing to cause havoc in my airport sceneries.
I have 17 sceneries, all active and were installed. I can see them in the E:\Addonmanger>Fsdreamteam) Something I have done has caused the message, Active but not installed to appear for all of them.
When I was at KSDF, FSDT did give me the option of activating its licence, it did and even backed up the licence etc. Now I have reloaded P3d, KSDF is now back in demo mode, and while it invites me(in addons>addon Manager>Louisville>register serial, I do this, but nothing happens. At KSDF, it is just a dark outline where the airport is. I have ran the live updater. It did have an issue first with C:/ProgramData/virtuali>couatl which it asked me to remove as the updater could not.
Anyway, I was hopefully trying to not replace all of the sceneries again and reinstall of??