I purchased Minecraft from the Microsoft store and installed on my WIN 10 PC.  I have done uninstall/install cycles almost every day since March 26th.

I have reset my Microsoft passwords from local PC to Microsoft, reset my MOJANG password.  I can not launch Minecraft (Starter edition) and log into my Microsoft account.  After 10-15 minutes, I sometimes get the attached "Failure.jpg" message.  Other times I get a black rectangle in the middle of the screen.

Turns out I was using the wrong version ("starter") for Windows 10, and not the straight Win 10 version. (DUH)