This happened with Pinheiro's Europe++ scenario. I was the creator and the only one experiencing this problem. This isn't the "bug" of no-one being able to pick countries when a scenario game is started--it actually worked for all the people here and the window
did come up.
Basically, I could not click anywhere on the map. Movement was possible with the +/- buttons, the minimap and the arrow keys though.
In the screenshot, I
rejoined the game and waited about 40 seconds just to make sure that it was properly buggering up. Even when I rejoined the same bug existed except that the timers didn't even show up now.
I was unable to play in
my own game due to this bug. One of many...