I have been successfully applying Melodyne as a Region FX  to clips to tweak pitch.  Today it seems I can create the Region FX and tweak pitch,  but when I render the clip all audio playback from any track ceases.  I can undo the render and audio playback returns.  Any ideas?
 
Best Adrian

How long are your clips ? Can you give some system specs, audio interface specs to help diagnose ?
How are you rendering the clip ?  . . . freezing or bouncing the tracks ?

Thanks for the reply.  I'm using a Behringer X32 Producer as the interface at the moment and the computer is hi spec and upgraded to Win10 with Sonar up to Ipswich.  Clips that cause the problem can be any length.  I have only tried bouncing clips within tracks.  It seems to me that if it all worked the day before it is strange that it suddenly starts exhibiting this behaviour.  Looking at the forum it seems there are a few issues with Ipswich and Celemony so,  having slept on it,  I am minded to re-install it all today noting that I only need VST3 for Celemony. 
 
thanks Adrian

Aah Sorry Guys I think I've solved it.  I had been fiddling with synch and cache settings to get rid of some glitching and tried the Sonar recommended cache setting of 32.  When I restored this to 256 it all worked fine.  I got rid of the midi glitching by increasing playback buffers from 4 to 6
 
best Adrian