FSX is for some reason not finding a hard drive where I have a lot of photo real scenery. The link(s) likely got messed up after I rebooted into my Windows 10 system drive and started FSX without establishing the scenery drive as K:, which is what it is under my Windows 7 system.  I believe the Windows 10 system saw the drive as G:

 

FSX starts to load textures but hangs at 0%.  If I pull that scenery drive from the system, reboot, and start FSX again I get "can't find scenery" errors when starting FSX, but once I run click through those and get FSX up and running it does fine. No issues, but of course all I get are the default scenery and my freeware addon scenery.  So it is clearly an issue between FSX and that drive.  

 

I did a deep chkdsk on the drive and it checks out. I can navigate throughout the drive with file manager, so the drive is not bad.  I used SceneryConfigEditor v1.1.2 to look at the situation and it was showing those scenery areas as errors, invalid path or something like that. But now that I have the drive nailed back to K: the SceneryConfigEditor v1.1.2 sees them on K: and no longer reports errors. Oh, and prior to that I had restored the scenery.cfg file from a week old backup.  I flew FSX without issues as late as yesterday afternoon.

 

Anyone familiar with how to fix an issue like this?

Got it figured out! Deleted the scenery indexes and forced FSX to rebuild them. Whew!