Good afternoon all - 
 
Running SPLAT using Akai Advance 61 to play EastWest strings (hollywood solo cello) along with already recorded audio tracks. Works fine, but as soon as I hit space bar to stop, I can no longer get any sound via the keyboard/MIDI. The controller is triggering because I can see the signal on the screen but no sound. No sound on the PLAY (the player window for EW strings) keyboard, either so I know it's not on the Akai side.
 
It's not disconnecting control by the Akai because I can see it triggering (and already tried, on a whim, disabling all the USB power saving stuff) - it just won't play any audio samples in the EastWest module. The other audio (already recorded) plays fine. The only way I can get the midi sounds back playing is to reload the patch on PLAY and it's all back to normal (until I hit stop again). And this is truly annoying.
 
Certainly, I'm just being an idiot here, so if somebody can tell me what I'm missing I'd be so grateful!

I do not have EastWest, so just a general guess.
Sonar sent a bunch of "CC reset" messages to Synth on stop. If some particular CC was changed/recorded (check with Event View), these CCs can be reset. Otherwise that are just usual messages which normally produce nothing bad. That is controlled by Sonar / Preferences / Project / MIDI / "Zero controllers when play stop".
 
If VSTi interpret some of these messages (f.e. for output volume...), that can produce strange effects. Can happened when ModWheel and/or PitchBend controls was mapped for some unusual articulation inside Synth and then forgotten to reset.

IT WORKED! Unchecked "zero controllers when play stops" and problem solved! Deepest thanks and appreciation!