I ran into this strange issue, V5 was going well for many months with several long hauls etc. Very recently I noticed an issue when i tried to add a new airport scenery via scenery Libray. So when I choose " add area" and normally it shows P3DV5 directly and entire drives and folders to browse through , instead it shows a single "Desktop" folder. When I move curosr around it shows "availability status error".
Steps I took after searching was >
1. Backup scenery CFG and delete so as P3D could build a new one ( didnt fix issue)
2. Tried repair using installer ( didnt fix)
3. Reinstalled the entire P3DV5.3 ( didnt fix and it remains same after reinstall as well)
I havent seen similar issue with anyone after many seraching. I hope somone can help!