The problem discussed in the posts I linked to is probably not being looked at by Cakewalk because nobody has been able to find a reproducible recipe to create the bug. If you can find a consistent way to create the problem from a new project, that would be very helpful.
 
My guess is that there is a bug in the FX bin code, since different plugins seem to cause this. In my case, it seemed to be the Sonitus reverb! Clicking the FX off button stops the problem.
 
Cheers, Peter.
 

And like Johnny, he's back!
 
Everything was working fine when I shut down last night.  Load up this morning to put some finishing touches on the mix and POP!  Cinebells channel again.  However, this time, even with all FX bypassed, the meters will still stay maxed and no sound will happen until I mute CB channel :/
 
I deleted the instrument from Kontact, reloaded it, and things started working again, except now the bus that CB runs into pops, until I turn off Neutron on that bus, run some audio, turn it back on and continue.  There is definitely an issue with the FX bin / chain.
 
I get it, Sonar hates me mixing VSTs and plugins.  If I switch to only working with stems, do you think this will go away?
 
 

Self-answering question I guess.
 
15 tracks of VSTs with 1 to 4 Waves / iZotope plugins on each is a little much.  Stems and FX only seems to be running smoothly.  For now anyways lol.  
 
 

CdrDave
And like Johnny, he's back!
 
Everything was working fine when I shut down last night.  Load up this morning to put some finishing touches on the mix and POP!  Cinebells channel again.  However, this time, even with all FX bypassed, the meters will still stay maxed and no sound will happen until I mute CB channel :/
 
I deleted the instrument from Kontact, reloaded it, and things started working again, except now the bus that CB runs into pops, until I turn off Neutron on that bus, run some audio, turn it back on and continue.  There is definitely an issue with the FX bin / chain.
 
I get it, Sonar hates me mixing VSTs and plugins.  If I switch to only working with stems, do you think this will go away?
 

I don't go as far as stems. Just bounce the VSTi tracks to audio tracks and archive the midi. Once you are mixing all audio tracks, things seem to settle down quite a bit. Many VSTi's put quite a load on the PC due to CPU usage or sample streaming saturating the I/O bus.
 
One workflow that works for me is to get all of my instrument tracks composed and arranged, then "Save As" a new project. At that point I can start bouncing and prepare for mixing. If I ever need to change an instrument track I can load the old project, make the change and export the audio. This works for me, YMMV.
 
Regards,
Dan

I doubt SONAR hates you personally, Dave ;) The great thing about standard interfaces such as VST is that all plugins communicate via a common language, allowing you to freely mix and match them with the assurance that there will be no incompatibilities regardless of how they're combined.
 
I'd focus my initial attention on Neutron, simply because it's a relatively new product and therefore more likely to have some obscure bug. The symptom of ludicrously-high levels can only happen when a plugin makes an internal math error. The circumstances wherein it commits that error could be data-specific, which may be why it occurs with a specific sample library. Whatever's happening, we can be pretty sure the library itself is not at fault.
 
BTW, what does the CPU meter show when this phenomenon happens?

By "bounce VSTi tracks to audio" do you mean just freeze the track?  And archiving MIDI - just copying the MIDI data to an empty MIDI track and dropping it in a folder or so?

bitflipper: Not 100% sure, but almost positive the CPU / HDD meters weren't abnormal.  Only the track and bus volume meter.  I'll check if it happens again.  Right now I have to meet a suspense, so I'm just going to play it safe, finish the COMP and only mix with stems.  Takes longer to make adjustments, but at this rate, it will actually be faster.

Freezing the synth itself is probably your best option.

CdrDave
By "bounce VSTi tracks to audio" do you mean just freeze the track?  And archiving MIDI - just copying the MIDI data to an empty MIDI track and dropping it in a folder or so?

I don't freeze VSTi's. I know others do, but I don't like to have my project carry all of that bloat around as I move through the various stages of mixing. Once I'm done tracking, I literally bounce and remove the VSTi. I always have my alternate project to go back to if I find something I really need to change.
 
Regards,
Dan

YIKES! I've just experienced the exact same symptoms as reported by the OP. Meters on the master bus pegged, no audio except for some clicks. I had to close SONAR, which had become unresponsive.
 
Unfortunately, like the OP I've so far been unable to reliably duplicate it, although I have repeated it several times. Each time it occurred after adding one or two effect plugins to an audio track, specifically RBass followed by Roth-AIR. 
 
Still experimenting...