The first time this happened, I restarted my computer (using restart and not a hard restart with a shutdown first) to refresh it and got the Dell Blue screen of death (I have a Dell computer) as per the pic below:

I was able to restart the computer with no apparent issue, but I understand this (the blue screen report) has something to do with a Windows issue of not being able to handle something...something perhaps caused by the game when it became unresponsive.
When I played the next day, I started with a PBEM NA scenario, then played a PBEM 39 scenario (without restarting anything), and everything seemed fine. I then decided to quit the game and restart my computer, which I did because I wanted to see if refreshing the game and my computer would get rid of the issue if I were to switch back to an NA game again, but when I tried to restart the computer (as before) to do so, I again got the Dell Blue screen of death!
I'm sure I have no hardware issues and my computer is more than capable of handling the game, which leads me to think that the issue may be with the NA scenario, as kennonlightfoot has also noticed. I did play multiple NA PBEM scenarios (only) going back and forth between then without restarting the game, before starting the 39 scenario PBEM games, and had no issues until I started going back and forth between the NA scenario games and the 39 scenario games. This leads to the possibility that if there is a problem with the NA scenario, it may only manifest itself when switching to and from a campaign scenario. I have no idea if this is even remotely possible...
Thoughts anyone?
Alvaro?
Thanks,
C