Start editor
Choose Altis or Stratis
Place a unit (player)
Press PREVIEW
Press escape
Press CAMERA
Press "H" (toggle overlay OFF)
Press "H" again (toggle overlay ON)
Open Map
Close Map
Now you should experience the bug as nothing happen when you try to move or look around.
Press "H" or click on some of the sliders in the right lower corner. Now you should be able to move again.
Also notice same happens if you press "H" twice and then toggle vision mode. But that is if you press "H" twice and without moving/looking around press "N".