Not sure when this problem started, as I haven't been mixing a lot lately...
 
Can anyone verify this behaviour?
 
1) Put a long reverb on a bus, play short snare sample wav file that has a Send to the Bus. Reverb decays okay.
 
2) Put a short processing VST (like EQ, or Channel Tools) before the reverb in the Bus VST chain. Hit play. Reverb decays okay.
 
3) Add another short processing VST after the reverb plugin (like EQ, Channel Tools, Limiter). Reverb decay is now cut off as soon as the WAV or bus send automation stops sending audio to the Bus, it seems.
 
4) Now remove the the 1st VST (the one before the reverb). Again, reverb decays okay.
 
5) Result... unless the reverb is the first or last VST (does this with other long VST processors, like delay, too)... the bus stops passing audio to the output.
 
This is repeatable, on a new Project, one track with individual, short snare WAVs, 1 Send to reverb Bus, Track and Reverb Bus outputting to another Master Bus.
 
Is there some new "feature" setting causing this that I missed? Or is this a bug? Or is it just specific to my system and settings?
 
I'm running latest version of Sonar Platinum x64 on Windows 10, x64 VSTs, i7 5930k, 32GB RAM.
 
Thanks for any help.

Update...
 
I am able to reproduce this problem using only Cakewalk/Sonar Platinum plugins, as well. I created a Problem Report ticket, and uploaded a CWB file as an example.

This seems like a possible VST3 gating issue.

That's what I thought, too. But it happens with VST2 plugins, too. I tried all VST2... same result.

It seems like you have been very thoughtful with your diagnostics. I hope you find the cause and a solution is made available.

See if adjusting Clip Tail Duration solves your issue.
 

This came up in another post recently, and I was unable to reproduce the problem with only one FX (CA-2A was suggested) ahead of the reverb, and nothing after it. But your description seems to be saying it occurs only when the reverb is sandwiched between at least two other plugins so it's neither first nor last; is that right?

For some reason I can't reproduce. The following is the scenario, yes?
 

 
So all I can do is guess at a solution...maybe I have different settings somewhere. In addition to what I mentioned above, try checking "Always Stream Audio Through Effects" under Preferences > Playback and Recording to see if that helps.

When I checked it, Always Stream didn't make a difference - worked either way. 'Always Stream' is more about what happens when the transport is stopped.

I just reproduced the problem on my master bus. When I moved the same FX to a track the reverb tailed off as per my decay settings.