Starting April 30th, Microsoft has been rolling out a big Windows 10-1803 update. This is one of those hour + long updates that won't be fun if you're trying to shut down in a hurry. You will need to do it.
It adds a slew of fixes, enhancements and obviously, parts that weren't broken before that now need to be fixed. The first release was Windows 10-1507 in 2015. Since then, there's been 10-1511, 10-1607, 10-1703, 10-1709 and now 10-1803. Believe it or not, if you have 10-1507, 10-1511, or 10-1607, Microsoft no longer supports you until you've upgraded to a newer version which should happened automagically.
If you press the WINDOWS KEY (usually found to the left of the space bar, and while holding it down, press R, it will bring up a RUN window. Type in WINVER and hit enter. You should then see an info screen with your version of Windows 10. I just upgraded my almost 4 year old PC to it Monday and it updated without a hitch. If you're on an older version, you can click on the Windows Icon in the bottom left of the screen, click on the Settings gear, and then click on Update & Security and it will hopefully help you there.