something went wrong while trying to turn on spatial sound

I actually got it working again.  Worked solid for about a months now.

I disabled all the ARC features on the tv, disabled all arc features on reciver.

I then Re-enabled the tv ARC and then reciever ARC.  

Tv and receiver have to be on first to reconize each other.  Then turn PC on. 

select dolby atmos and it worked.

lg tv labels arc as simplelink.

onkyo arc hdmi cec.

Hope this helps.  

It broke twice in a month.  Computer was on before reciver turned on.

Has to be a hand shake issue with all the components and security i bet.

Good Evening All, After reading everyone's possible fixes and trying them myself. With no luck :(. I have almost given up but than decided to do the old tried and true method. I unplugged my Vizio SB36512-F6 5.1.2 Atmos Soundbar for 30 seconds while the computer was on with my speaker setup as 7.1 than plugged it back in and opened Dolby Access and ran the setup and switched Spatial Format to Dolby Atmos and it worked!!!!! Let me know if this works for anyone else. Thanks.

one of the main ways why u cant turn spatial sound on is due to the nvidea hd audio driver... remove it by going to device manager-> sound, games... and then install intel hd audio instead which is already available in windows 10. Your atmos will hopefully turn on.

doesnt help.

I actually have the same problem on my gaming computer that has a amd ryzen 7 2700x and a rtx 2080ti that's on rs5 but the weirdest thing is that my other computer that is way lower end and has a amd ryzen 7 1700 and a gtx 1070 and on a beta build for 1903 has it working great. Why would a older public build have newer problems that a newer beta build does not have at all? And why would the problem happen on a computer that is running the newest tech from both amd and nvidia vs not happening on an computer running older tech from both amd and nvidia? I'm a win 10 beta tester and I'll definitely admit these issues just don't show up in beta builds so we as beta testers can't catch them and report them ever. The reason ms has to always call back the builds that just become public is because there are bugs like this for example that only show up after the build has been made public. Aka they never show up during beta. I know that for a fact as a win 10 beta tester.

Update for nvidia video card people it definitely is the nvidia hd audio driver. As someone mentioned in earlier in this thread changing the nvidia hd audio driver to regular hd audio driver fixes the problem. I did that and now I have Dolby Atmos working perfectly again. It also fixes the other problem I had where if I would switch programs while having Dolby Atmos enabled after I switched programs I would get no audio at all until I switched the audio settings from Dolby Atmos then to regular 7.1.