I can't get it to work either when I double click. I have it in my downloads directory also. It did give me an option to extract the files so I did that and put them in my FE mods directory. Still didn't work when I ran the game. Is it supposed to come up in the game or is there an exe file? I didn't see any exe file in the extracted files, but I gather that's not the way to go anyway. Shogun, what did you do to get it to work? Will the editor allow me to use Heavenfall's races, without his faction info, if I ever get it to work?
It shouldn't extract files at all. The jar file is an executable java file. What extracted files (winzip, winrar, etc)?
To run it manually, run this in a command prompt (in the directory you downloaded it to):
java -jar FEEditor0.3.1.jar
EDIT: No, it doesn't run in the game. And as of right now, it doesn't completely pull in mod folders. You can set one mod directory, and it will pull some stuff (like starting units), but not everything yet. This is still being worked on.