I've placed several airports (folders) in my Add-On Scenery folder and have then gone to my Scenery Library and added those folders to the library. My question is whether I should leave the "Add-On Scenery" checked in the library (I'm referring to the generic item, if that makes any sense) as well? Thanks!!!!!

Leave it checked (active) !!!!It has a scenery subfolder (and texture too) and if do not already have some afcads and or other bgl files in the scenery subfolder, you will before long as many authors suggest that you put them there.So the bottom line is - keep it activated.

If you dont have anything inside the add on/scenery folder except those new airport folders, then yes you can un check add-on scenery. The poster above is also correct but If there is nothing in the add-on/scenery or add-on/texture folders you dont have to keep it checked. FS is actually just using the add-on scenery folder as a place to look for your new airports (their own folders) You can actually have the add-on stuff in its own folder anywhere on your hard drive you want. FS looks inside the folder you specify for a scenery folder and a texture folder. What is inside these is what it uses to display the add-on. Hornit