I have the very simple solution 🙂
I had the same issue that the GSX menue does not open after using the weather request from ActiveSky... SO you have to stop closing the ActiveSky/GSX window by using the mouse instead of choosing the exactly line in the menu is shown ("Close Window") . It seems that the menue doesn't really disappears in the background when you just closing it with a right mouse click on the window so that a second menue is blocked because the other is not correctly closed with the function in the menue...
kind regards