Here’s a quick test. Fire up or reboot your Win10 machine. Click inside the Search box on the lower left. You should see something like the screenshot I posted on Computerworld two days ago. This morning, though, many people are reporting a completely black screen, as shown in this screenshot of a recently patched Win10 version 1903 system (Build 18362.592).
In addition, Search simply doesn’t work: Type something in the Search box and nothing happens.