32 minutes ago, Jim Young said:

Do you own DD New York City X.  I have it installed and New York Airports v2 is located above that in my add-on.xml's.

I do not own New York City X.  All of my airports that I have installed are "greyed out" in the scenery library and cannot be moved up or down.  Could it be that they are higher up than something and that is causing it to happen?

The scenery.cfg for P3DV4 is specially coded.  If it gets corrupted, you have to rename it, restart P3D and let it rebuild.  Once rebuilt, you can go to the scenery library inside of P3D and manually add any scenery.  Adding scenery to the P3Dv4 scenery.cfg is not recommended.  I use Lorby_Si's AddonOrganizer (see Lorby_Si Freeware Forum here on AVSIM).  If you want to add scenery, just click on Add Scenery go to where the scenery is located and add it.  You will also have to go to Components under Other Addons and add the Component "Texture" by going to the scenery's folder and click on Texture.  If there are any other components like Autogen, Scripts, SimObjects (usually in the same folder as the installed scenery), then these are added too.  You can move the scenery up or down in the AddonOrganizer.

I have all of my scenery (some made for FSX) using the Addon Organizer so there is no Addon Scenery in the scenery.cfg anymore EXCEPT I use UTX2 and that is turned on or off by going into the UTX2 utility.  I also have FTX/Orbx areas and scenery but so far have not added them to P3DV4 but, if I did, FTX Central 3 would add those sceneries.  I have removed my P3D scenery.cfg from the SceneryConfigEditor which was so convenient in previous versions of P3D and FSX.  Just use it for FSX installations.  Opening the scenery.cfg in the SCE is risky as you risk corrupting it and you will suddenly see no scenery in the config or the scenery will load but P3D will suddenly crash with no explanation.  It needs to be in UTF-8 format.  I think LM is going to fix some of this in v4.1 as it is wrong that sims crash for unexplained reasons or the scenery.cfg gets corrupted just because a developer wanted to use it to install their scenery program instead of using the Addon.xml methods.  Oliver at Lorby_Si has done an excellent job creating the Addon Organizer!