the editor itself starts but, when i try to change stats, it hangs. that prevents development of maps until it is fixed.

+1 me too! The game also hangs when I try to go in "Scenario -> Resources" and my mouse scroll disappears!

How do you even open this actual scenario editor, with the map?

I can only find map editor, and the scenario editor only allows to change some settings, but no actual map editing for the scenario conditions like in your screenshot.

the stuff in the screen shot is accessed by clicking on resources on the scenario menu. unfortunately for me, it hangs and i can not use it. i hope that gog manages to fix that. i am rarely on gog however so, it might take time before i answer any posts you make.