I just noted that there is a new popup on my Windows 10 Pro stating "Activate Windows". As far as I know, my Windows has always been activated. Called M$ and after a half hour wait, tech support responded that this was an ongoing problem, and I should wait for them to fix it. Waiting on line is the story of my life.
As Jane's link pointed out M$ activation servers were messed up for a bit and some cases not activated messages popped up. Others it said they had Pro installed where they were actually only licensed for Home etc. I believe they have it fixed now but it does point out a flaw in their current method of activation where it can mistakenly cause problems.