I went to do some editing last night and Melodyne Studio worked fine except there was no sound output.  The meter was moving but no sound.  In other words, I could not monitor from inside Melodyne. I tried it on several different tracks, reboot, etc., nothing.  I went to another song and Meloldyne worked fine so there must be something wrong with this particular project.
 
This project was originally done in 2013 and I used Melodyne Editor on some of the tracks at that time.  When I first opened the project I got a "No synth output found" for Melodyne message, which is very interesting, as I've never put Melodyne in the synth rack and I don't know how one would use it that way.  Initially, I ignored this error message but when I found that Melodyne was not working, I tracked it down and deleted it from the synth rack.
 
Has anyone ever seen this?  Any suggestions would be greatly appreciated.
 
TIA
 
Paul

Yes, this has been happening to me recently. No sound from Melodyne, but SONAR plays fine. I need to look closer at it.

This also happened to me last night. Very annoying. If you click on a Blob, you see the meter moving, but no sound. If you press play you hear it, but it is very hard to edit any data. Seems like it is Sonar, because Melodyne works perfectly in stand alone mode.

http://forum.cakewalk.com/SOLVED-Melodyne-not-playing-sound-when-moving-quotBlobsquot-m3437843.aspx
?

Thanks!

This is sort of solved.  I opened to this project last night and the 'Disable all FX' button was lit.  That is not something I ever 'set and forget'.  I undid that and Melodyne worked on everything I tried it on except one track.  I deleted the clip I was trying to tune in that track, recopied it and viola! it worked.  I can't explain what happened but I was able to tune all the vox tracks in that project and everything worked fine.  Go figure....
 
Paul