Creators Update broke Windows Key & Start Menu

My laptop is an Asus ROG Strix GL502VS and CU failed to install so it rolled back. After rolling back, however, the Windows Key and Start menu no longer work. Press Windows key, nothing. Click on Windows icon, Start menu doesn’t appear. Needless to say this renders Windows 10 almost unusable.

Searching the web, none of the easy fixes worked for me. But creating a new user account did the trick — for that new user. Although having to reinstall from scratch would be much worse, this work-around is still painful.

Is there any way to restore Windows Key/Start Menu functionality once it’s glitched out like this?