For some reason, Halion Sonic is only showing an ALL option now. When I click on it and filter by instrument-like piano-I can scroll through a bunch of stuff and find the Elements pianos, but the individual display icons for HSO, Elements, Iconica Sketch, etc. that used to be visible no longer display. I have attached 2 images of what I see. I have the updated media bay and the libraries are listed in the Library manager. They just don’t display in the Halion Sonic within Dorico. Elements and Iconica Sketch are also missing from the stand-alone Halion Sonic. They all show as installed in the Download assistant. Any ideas as to what happened? Thanks!
Yes. That’s exactly my problem. I did, in fact, re-install Halion 7. Thanks for that link. I’ll try it.
Odd. Here is what I see now, but Iconica Sketch, Etude Elements, & Olympus Choir still don’t show - though they are installed and in the library.
It’s not too big a thing as all my loaded sounds are available, but it was nice to just ‘click on the pic’ of Etude Elements et al and peruse just those sound library options.
Have you tried toggling the “All” button a couple of times?
Thanks. I shall do so when I’m back at the computer. 'Tis a puzzlement.
I got a new message when Dorico wouldn’t connect to the audio engine that the Media bay could not be reached. Now when I click on the “All” there is absolutely nothing. I’ll try reinstalling the media bay. Curiouser and Curiouser 
Well, that and reinstalling the Media bay didn’t work. When I select ‘ALL’ I get none 
Well, Thanks to all who tried to help. HSO, Sonic Selection, Indian Drums , Marching Percussion, Trip, Alto Glockenspiel and Flux now show in the Halion window in Dorico.
Iconica Sketch, Olympus Choir Elements and Etude Elements still do not. All are in the library manager. I’ll try to live with it. It’s not a HUGE thing as the sounds are still available to me; just not as easy to find.
O frabcious day! Hooray, Hooray! I got it working. I uninstalled everything, cleared the Program Data/Steinberg folder items and then reinstalled everything. All seems well now. Me thinks if I could afford to, I’d get a Mac 
Thanks to all of you for your willingness to help. It is GREATLY appreciated!
Well, almost… Iconica Sketch and a few other displays seem to want to play peek-a-boo; sometimes they show, sometimes they don’t. I give up. All the libraries are available to me-that’s all that really matters.