Somehow, this build has got stuck. I cannot bring up the Start Screen either by hitting the Windows Key, clicking the Start Button or by hitting Cntrl + Escape.
I also cannot bring up the Notifications screen to flip in and out of Tablet Mode. This usually brings back the Start Screen.
A final resort: Since I am running Windows 10 under VMware, I can click the 3-squares-icon (Send Ctrl+Alt+Del to virtual machine). This succeeded in bringing up the blue shutdown screen, but none of the options (like Shut down, Restart or even Cancel) have any effect.
********** THIS LOOKS LIKE THE END OF WINDOWS 10 **********
To add insult to injury, I can turn on Narrator and it dutifully tells me what I am doing — AND THEN THE OS DOES NOTHING !
Build 10122 – Narrator On, but still unable to Close