I deleted Cubase preferences (ctrl alt shift) on Cubase startup and it didn’t fix the problem. I don’t bother saving Cubase preferences because I only change one preference anyways.
So I did the usual and restored Windows to Dec 29, 2013 and that fixed the problem. No other programs were affected because no programs were installed since Dec 29.
I have no idea why this happens periodically but it does happen and it’s very irritating. If I ever figure it out, probably by accident, I’ll certainly post the fix on this forum.