Okay, so the first thing that you can try is to disable all other plugins and try it again.
Second, press F12 while testplaying to open the debug console, and (super important) navigate to "Console". Sometimes, you find useful information here.
Third, check your game directory. My plugin always creates a new folder "uicustom" with some HTML and JS files. The lack of this directory and the files can indicate that my plugin didn't even start with the game.
Finally, I've heard of people where the F9 key simply didn't work. You can test it by pressing F9 while being on the map, and check whether the debug menu (where you can inspect Switches and Variables) opens up or not. If not, you can tell my plugin to use another hotkey by following this procedure:
- Open my plugin with a test editor
- look for "debug", and replace it with "control", "pageup", "pagedown", "shift", or "tab"
The next update will include an option to manually set the hotkey, so you no longer have to do it manually.
Hope this helps!
EDIT:
Sorry I forgot that you already tried disabling other plugins in your first post























