Problem solved....
I'm not very techy, so my explanation might be simple, ... but in an effort to help someone who might have this issue in the future I'll try to explain.
It had something to do with a feature called "Direct Play" ... some kind of legacy software that Windows blocks from Windows 10.
And that was combined with a known Windows 10 bug in which the ability to turn features on and off just hangs up blank.
It required some Run:CMD action (which always makes me nervous) ... and a restart ...
but that fixed it.
( and I got in ... of course I log in with Hully and he's down in the UD at Barren Rock ... which I used to totally remember how to get out to the surface from ... but now have no clue

)