No sound for selected instruments

All over sudden, upon resuming work in Dorico, I found no sound for harp.
The puzzling thing is that instruments such as violin, viola, flute do sound, yet harp (which sounded just yesterday) nor piano don’t yield any sound; neither when inputing notes from the midi keyboard, nor in playback.
Looking at the Halion Sonic SE2 panel, I see that the channels for piano and harp are empty - i.e. there are no names such as Violin Solo Combi, Flute Combi.
Deleting VSTAudioEngine in Preferences didn’t help.
I’m on iMac 27’’, 2.8 GHz i7, 8GB of RAM
Needless to say, that any advice on how to remedy the problem will be greatly appreciated.
Igor Borodin

I made a quick test - a new project with just Harp.
The Halion panel lists it as ‘First Contact’ and displays the following message:

What if you go to Play Mode and choose from the menu Play > Apply Default Playback Template?

Hello Ulf,
Since posting about this problem, I re-installed Dorico.
And now the situation a bit different.
Violin (and some other instruments) are using Halion. Here is the screenshot:

But Harp while giving the sound, seems to use GM :

I followed your advice, but it didn’t change the situation.
Once I add harp player, it looks like for a second Dorico does load yellow label, but then immediately changes to GM

Any advice would be very much appreciated.
Igor Borodin

P.S. The order of screenshots is reversed - the first one shows the case for harp and the second - for violin.

When adding a Harp player that’s what I get too, I don’t think there is a harp in HSO…(?)

For me, the Harp defaults to the Classical Guitar patch. Neither is very attractive, and I say that as a guitarist. My guess is that Dorico is counting on users employing the various sound libraries that they own, as opposed to providing a complete library “en suite.”

Thank you guys for the clarification.
Fratveno, you’re right - looking at the instruments in HSO, I can’t find a dedicated Harp patch.
My doubts about about harp sound arose from the perception (apparently wrong) that before my installation of Dorico got corrupted and I re-installed it, the harp sounded more full and ambient.
Well, I’ll play with EQ and reverb settings in the Mixer.
Thanks again for helping to sort this out.