I've had some recent issues with Melodyne changing the volume of and adding some geef (use your imagination - it doesn't sound good, does it?) to the processed clip. Fortunately, everyone I record has a perfectly in tune voice so I don't need Melodyne - I just use it to throw in a few pitchy notes once in a while so people don't get jealous of the flawless vocals - and because it's free with SPLAT.
 
I haven't had the time to experiment with any solutions but Ed the Bapu gave me some pointers (always make a copy of the track and set it to 0dB before Melodyning) that I expect to try.
 
Maybe Celemony and Cakewalk will get together and work this stuff out if we stop saying "ain't no big deal". It is a big deal when you're actually trying to get something done. 

Weird...  I've been using Melodyne pretty heavily for the last three days in Kingston and have probably processed 15-20 clips on multiple tracks/lanes without issue.  Granted, I always render the results after each clip is done (a carry over from using VVocal).   The project has about 14 audio tracks, CA-X amp sims on 7 of those tracks, Kontakt, multi-out AD2, a few Aux Tracks (one with GR5), and PC plugins scattered all around.  
 
This is on Win7 running on a Q9300 w/ 8GB RAM and a Focosrite 18i6 using ASIO.   I see most sigs include Win7 so I wonder what is so different.   FWIW, I typically have an active internet connection via a USB adapter but rarely have a browser open.
 

TStorms
 
 
Maybe Celemony and Cakewalk will get together and work this stuff out if we stop saying "ain't no big deal". It is a big deal when you're actually trying to get something done. 

 Sorry guys - my experience is similar to Steves -  running melodyne editor under Kingston platinum on Win 7. I use it often and it is rock solid. Probably time to do some of our own System trouble shooting rather than waiting or a fix from Cakewalk  as it would seem the problem is not universal with Sonar.

tenfoot

TStorms
 
 
Maybe Celemony and Cakewalk will get together and work this stuff out if we stop saying "ain't no big deal". It is a big deal when you're actually trying to get something done. 

Sorry guys - my experience is similar to Steves -  running melodyne editor under Kingston platinum on Win 7. I use it often and it is rock solid. Probably time to do some of our own System trouble shooting rather than waiting or a fix from Cakewalk  as it would seem the problem is not universal with Sonar.

Maybe the problem it's related to Windows 10,don't you?

Whatever the problem, Cakewalk/Melodyne or something goofy with user system configuration, it isn't strictly Windows 10.  I'm still running Win 7 and have had occasional Melodyne issues from X3 up through Splat JP.

I'm on Win7 also. Melodyne has been trustworthy for me in the past but not so on Kingston. I can also say that I've only used it on one Kingston track - so I can say it's been broken in Kingston 100% of time

This is an interesting thread! I've always had great success with Mielodyne in Sonar Platinum. But I haven't used it over the past couple of months or releases. So this is interesting and surprising. I haven't yet dug in to see what's happening on my end yet.

I'll be watching this space.

I had the same problems as the original poster. I'm relying on memory here, so I could be wrong, but I uninstalled Melodyne and then reinstalled it by downloading directly from Celemony and registering it under my Editor license, and it has worked properly ever since.
 
When I run updates via the Command Center I make sure I don't run an install or update for Melodyne. 
 
My theory is that doing so causes a miscommunication between Sonar and Melodyne, making Melodyne think the user has only the license bundled with Platinum rather than the Editor license. 
 
Anyway, the problem ceased after I did this. Worth a try. 

Sorry, been away for the last couple of days. Appreciate the comments from all.
 
 I have never re-installed Melodyne Editor with Splat, deliberately staying away from installing anything from CCC like Dimension Pro, Rapture, Cake instruments, etc. They are all previously installed on another drive, including Melodyne, and I want it to stay that way. Melodyne for me has always been quirky. If I do too large a clip, or leave any Melodyned unbounced clips in tracks, things usually go haywire. Nearly all my projects are created in a certain fashion. I record my ideas with acoustic until I have the song format down, create a new track, copy and paste the comp'd and bounced track to the new track, and delete all other takes, ensuring all instances of Melodyne are gone. Then I will create the drum track, and then begin recording all instruments. Then I save as a new project to begin editing, ensuring all recorded work is kept in an original file. In the new project I will Melodyne, tempo change etc, all the usual stuff, to my hearts content, but always ensuring that I only do small parts at a time, rendering down as I go. The finished comp from each track is copied to a new track and rendered again. There will be no clips left unrendered. Once I've done all this, I will delete all tracks with takes and save as, again, to a new project, which will only contain one rendered track for each instrument, and work on vocals begins, but follows the same pattern as above. I have found this to work for me. If I don't, everything seems to continually trip up and crash, probably based around whatever effects I've inserted, but in my mind, most of my workarounds and workflow choices, are based around getting Melodyne to work without crashing my projects continually.
 
It is a great piece of software, as is Sonar. I'm not complaining really about either, except on days when I am trying to work, have artists in recording, and I have to stop for hours, sometimes days, to work out yet another problem. I come from the tape days. The digital days are just incredible. But as I get older, I get more frustrated I guess, because I just can't keep up with the amount of knowledge required to keep working uninterrupted. A rant maybe, but it's very real to me.
 
So I not happy that others are having similar problems, but I'm heartened that if I'm not alone, the problem will eventually be looked at and hopefully fixed.