Thanks for your speedy response.
I know that -- in theory -- I don't need the CD. And we have played dozens of times across the spectrum of COI, West Front, and Ardennes, plus as noted we got through the first op of Barbarosa.
Be that as it may, I was still told I needed the CD, even after rebooting COI. Where I work, we call this a bug, and perhaps the developers will, if not respond (which I don't necessarily expect, as I am sure they are very busy), at least note this report. I did not see anything relating to additional files, but I will save my game file elsewhere, and then reinstall COI and possibly Barbarossa as well, and see if that produces a positive result.
I think the game was just mad because the Russians held off the Wehrmacht.