"deactivate" in the settings file, and "activate" in the conf.ini is how my settings were and the escape key is not working. What's strange is that the escape key works in the Main Menu, but not in a mission. Any other suggestions?
EnduringPaper: I think it should be "deactivate" in the settings file, as it is so for me. However I discovered it should be "activate" in the conf.ini under [HotKey gui]. Maybe it's somehow missing from your conf file, or assigned to something else?
You could also verify if perhaps you have accidentally assigned the escape key to another control? ...Well I guess it is assigned to bring up the orders comms now that you have changed it in the settings files, if you didn't change it back haha.
Now that I think of it, I sometimes have a problem where the mouse is not responding in the game (usually from having focus on another window as the game starts). Perhaps you're experiencing something similar with the escape key? Try to alt-tab out of the game (and I suppose press escape once while tabbed out of the game, for good measure) then return in the game and see if it works.
I hope any of these solutions work out for you.