I have been mixing down a live recording of 16  tracks.  Most of the show can use a standard mix, only varying the lead vocal a little.  But there are a couple of songs that have some instrumental solos where I need to adjust the mix a little.
 
This seemed like the perfect use for scenes.  Long story short, I can save the scene changes,  And I can recall them, which does put all the changes into effect, as expects.  But after that, there is no sound.  I can see the sound on the individual tracks, but nothing gets to the master bus.   I am using sub-master buses.  One of the three subs seems to get sound, but it doesn't route to master.  And the other two subs don't get anything.  I can't fix it by reassigning the outputs.  But if I close Platinum and start it back up, everything works.
 
Anybody else have this problem?

Never run into that so far. If you can upload your project or a way to repro we'll investigate it.
One thing to try to eliminate the audio interface - try it with the default onboard sound device. Also disable restoring masters in the mix recall settings and see if that makes a difference.

Noel Borthwick [Cakewalk]
Also disable restoring masters in the mix recall settings and see if that makes a difference.

It probably isn't practical to upload the project because it is an hour-long program with 16 tracks.  I can send a DVD if necessary.
 
But I did play with the advanced settings.  I unchecked bus controls, bus automation, bus FX, mains, and auto-save.  After that, switching scenes worked each time.
 
When I checked Bus Effects, the problem returned.  I do have some effects on my buses, of course -- That's why I set up those buses.  To be clear, if I have everything checked EXCEPT Bus FX, it works fine.  It fails when I have Bus FX checked.
 
Here are my effects
  Vocal bus has two sends to S-type compress on each of the other two buses for ducking.  And the vocal bus has its own S-type compressor.
 
The other two buses have the S-type compressor mentioned above, and they also have the Concrete Limiter.  Nothing else is turned on.
 
My guess is the side-chaining is getting messed up on scene changes.
 
 
 
 
 

I suspect the Concrete Limiter is possibly causing the issue. I have run into that in the past albeit I couldn't reproduce it at will. You can check if that is the issue quite easily.
 
When you get complete silence take a look at it. If it is the CL it will be applying 100% gain reduction even though the settings aren't set up for that.
 
Having said that I thought that had been fixed in an update, or at least I haven't seen it at all in quite some time now. If it is the CL it'll be worth checking that you have the latest version installed.

I also suspect Concrete Limiter. Something happens to me quite often and it's always Concrete Limiter.
When the audio is not being passed, check out CL and you'll see one of the meters completely full, bypass CL and the audio will pass.
I have reported the issue in the past with Problem Reporter and tech support had been able to reproduce it.
The CWBRN-28713 shows as status changed but no mention of if/when it will be fixed.
The only workaround is to close and reopen the project.

Yes it looks like you have narrowed it down quite a bit to the bus effects. Try a process of elimination by removing the effects one by one on the bus till you don't have the problem.
I doubt it is the sidechaining but will wait for your tests ...
 
BTW if you do need to send the project, you should be able to save a bundle of a small snippet of your project by deleting most of the track data leaving a few seconds audio. As long as the problem persists that will be sufficient to replicate the issue.

Sorry about the delay.  This was a week that had a bunch of projects due.
 
I have stripped this project down to the essentials.  There are now just 3 tracks -- each going to its own sub-master bus.  I bounced the audio down to a small section, so the download is only 15 MB.
https://app.box.com/s/f0ec9i73cb1mk2r43s3m96szrrrwsjx8
 
I did not strip away all the effects.  After all, it should work with all these effects.  The problem can be repeated every time.  There are two scenes, "normal and solo".  If you alternate between the two scenes with "Bus Fx" unchecked, it is fine.  If you alternate between scenes with "Bus Fx" checked, the audio no longer plays.  But if you save the project, exit and restart Platinum, the sound plays fine again.

Hi I looked into the issue. Thanks for following up and providing a repro case. 
Its definitely caused by a bug in Concrete Limiter and not a fault in Mix Recall. Mix recall has a knack for revealing bugs in other components :)
The Concrete Limiter issue is already fixed internally so once its gone through some regression testing we will release a patch for it.
For now you should be able to workaround it if you remove the concrete limiter or skip recalling the fx on your bus.