something went wrong while trying to turn on spatial sound

I had a feeling it could possibly be NVidia audio driver.  Maybe the latest driver is decoding audio instead of letting it pass through to the receiver for decoding.  Now off to Nvidia forums.   How did you find out version 399.24 would work, trial and error?  Or you went back to the oldest allowable.  Trying it tonight.

Well, guys. I've read through all the posts and decided to help those who have the same issue and setup like mine. As for the  latter, I have Windows 10 Pro x64 with Dolby Access installed, my PC is connected via NVidia Display Port to HDMI port in Onkyo TX-NR575E (Dolby Atmos enabled) AV receiver (Not sure if it's important but CEC and ARC are both enabled in Onkyo).

So when I first installed Windows I could easily select "Dolby Atmos for home theater" option and perfectly play Dolby Atmos content (via Dolby Digital Plus stream in my case), until some days ago, when it became unselectable. Well as most of you I spend a lot of time trying to figure it out, but then I noticed, that my receiver is connected via NVidia High Definition device, not Intel one (as for most posters here). So that was my lucky guess.

What I did next has solved the issue:

I manually deleted all NVidia audio devices in Device Manager (no reboot);

Having Nvidia 415.xx Driver installed I've downloaded 399.24 driver (just selected the one at the bottom of the list);

Installed 399.24 driver, selecting Custom Install and checking "Clean Install" checkbox (reboot);

After that I checked the Sound settings, but I was still unable to select "Dolby Atmos for home theater" option.

So I uninstalled Dolby Access app, reinstalled it and launched it. At this point the app asked me to reboot which I did.

After boot, I was able to select "Dolby Atmos for home theater" AGAIN! And play Atmos content of course! ))

Not sure you want to rollback to older driver, but I just described what I did to solve the issue, and all you need is basically the clean install Nvidia drivers, as well as reinstalling Dolby Access app. That's it.

Hope it will help.

P.S. Despite the fact that my Onkyo is Atmos enabled and capable (being connected to XBOX One X it's showing Dolby Atmos on it's screen and in input info), in Advanced sound settings on my PC I don't have Dolby Atmos on Supported Formats tab...

I don't know if they just updated VLC player or Windows but my Atmos is suddenly working again from VLC from my media Pc. Early last summer was the last time I saw this when I was trialing a Nintendo Switch my MediaPc started pushing out Atmos and stopped again shortly after it was removed. So this is the second time in a year I've seen it working. Lets hope it sticks around this time.

Have the dolby app from windows store.  Installed and spatial sound did work with atmos serting.  Now however i get a windows error message that format not supported.  I forget the exact verbiage but its posted in the beginning of the thread.   

Hdmi 18gbps cable going to receiver, onkyo, thats 4k compliant.  From receiver to LG 4k C8 TV.

overwatch works great with atmos, about the only game now that i’ve run that supports it.  Sadly its broken now.  Microsoft, please fix this.

Same for me. Worked when I did a Winsows 10 clean install. The next day gets the "Format not supported" and the Dropbox for Atmos for Home Theather in the sound settings reverts back to the previous setting. I think, at least, we are getting the same/consistant errors.

The thing that makes me worries is how this could slip through unit testing, acceptance test and the whole DevOps-process unnoticed. What kind of quality procedures are at place at Dolby/Microsoft?

Have the dolby app from windows store.  Installed and spatial sound did work with atmos serting.  Now however i get a windows error message that format not supported.  I forget the exact verbiage but its posted in the beginning of the thread.   

Hdmi 18gbps cable going to receiver, onkyo, thats 4k compliant.  From receiver to LG 4k C8 TV.

overwatch works great with atmos, about the only game now that i’ve run that supports it.  Sadly its broken now.  Microsoft, please fix this.