No sound during playback (new)

Suddenly … I’m not getting any sound during playback. I’ve reset everything to factory in the Play options in the Preferences. Like I said, this just started (not) happening. I was also working on a Logic project, but that shouldn’t interrupt Dorico since they don’t use the audio engine at the same time. (Correct?) Any way, I quit Logic and Dorico still doesn’t play back. I’ve also quit Dorico and started again. No luck.Nothing’s muted in the mixer, and the volume is all the way up for the master and Halion channels. I’m not sure what other things I can check in the app.

Check which output device is chosen in Edit > Device Setup. Carefully check the settings for that device in the System Settings (née Preferences) pane. If you’re still having no joy, please do Help > Create Diagnostic Report and attach the resulting zip file here.

Still no luck. Sound works fine in Logic and (sorry!) Sibelius. Also from the Internet (e.g., YouTube). I also discovered the activate/deactivate playback function but it seems that project is indeed “activated.” Here’s the requested diagnostics file.
Dorico Diagnostics.zip (862.6 KB)
Here’s the file itself:
Oleo TAB.dorico (868.1 KB)

BUT - just for curiosity’s sake I created a new file and the sound works fine! So it must be some setting somewhere that is preventing the sound from happening.

No sounds are loaded in the HALion Sonic virtual instrument. Try going to Play > Playback Template and re-applying the default playback template.

Yay! That worked. I didn’t know which was the default playback template so I just picked the one that was highlighted. Not sure how that became unchecked, but it’s working now.
Thanks again!