Introduction
When you install the Steam/GOG ports of Jedi Knight and try to use JkEdit it flashes an error at you.
This is because JkEdit cannot find the resources to the game. Unlike JED where the program has a configuration menu that lets you select where the game is installed, JkEdit relies on the Windows registry to find the files. The Steam/GOG versions of the game don't appear to set these up correctly.
However there is a very convenient fix for this I'll outline bellow.
Steps
To fix this open Regedit by going to the start menu and typing in "regedit"
Next in the top menu bar navigate to
Computer\HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\LucasArts Entertainment Company\JediKnight\v1.0
Next right click in the folder and select "New->String Value"
From here type in where your game is installed to. This is commonly
C:\Program Files (x86)\Steam\steamapps\common\Star Wars Jedi Knight
After this restart JkEdit and it should now start up correctly.
If you want further help with Jedi Knight modding I recommend joining the Massassi discord server
If you would like help getting started with JkEdit I suggest reading a tutorial I previously uploaded here.