Something is not working correctly!
Two days ago, after running Live Update, six of my FSDT sceneries were suddenly in Trial Mode and had to be reactivated. (I have a post elsewhere about that.) Now after reading this I just opened P3DV4.5 and activated a stored Scenario at CYVR. The airport was not there. Clicked On the ADDON Manager, checked and CYVR was listed as ACTIVE. Closed the ADDON MGR and, lo and behold, CYVR was there.