Celestia proceeds in alphabetical order (in each level).
first the folders, then inside the folders, the subfolders, and then inside the subfolders, the files
The name given to folders and files is important
example:
folder A
- subfolder AA '
- AA'a file
AA'b file
AA'c file
- AB'a file
AB'b file
AB'c file
- AC'a file
AC'b file
AC'c file
- subfolder BA '
- BA'a file
BA'b file
BA'c file
- BB'a file
BB'b file
BB'c file
- BC'a file
BC'b file
BC'c file
- subfolder CA '
- CA'a file
CA'b file
CA'c file
- CB'a file
CB'b file
CB'c file
- CC'a file
CC'b file
CC'c file
imagine that Earth.ssc is in CB'b and that moon.ssc is in AA'c.
Celestia will scan the dosiers in alphabetical order, so it will start with the AA 'folder to end with CC'
Celestia will load moon.ssc before Earth.ssc but as "Sol / Earth" is not known at this time of loading, it will detect an error and not keep loading moon.ssc in memory.
Result: you will not find Moon in Celestia.
The solution is to number the folders, and similarly number the subfolders and finally number the files, in the order they should be loaded.
Example:
extras /
1-solar-system
- 1-Star
2-Planets and moons
- 1-Mercury
2-Venus
3-Earth
1-Earth x.ssc2-Moon.ssc1-Deimos.ssc2-Phobos.ssc6-Saturn
7-Uranus
8-Neptune
4-Asteroids
5-comets
6-others
3-spacecrafts
When loading spacecrafts, all planets, moons, dwarfplanets, all asteroids, all comets, ... will already be loaded thus avoiding errors.
