In my workflow, I create a clone of whatever track I want to perform "surgery" on (e.g., gain leveling, reversing, MD edits, etc.).
I can then archive the original.  I always have that as a fallback if I find later that I have an artifact from the edit(s) I made.
Sometimes I'll see these artifacts more once I've compressed, EQ or saturated the track or in the context of a more final mix..  I then have the option of going back and starting over with the original track.
 
(Warren Huart made a similar recommendation in one of Produce Like a Pro Academy videos (https://www.producelikeapro.com/).  So I'm in good company LOL.)

thorneven
I found that the 64 bit version failed to install, but the 32 bit version installed fine. So I uninstalled all of it and reinstalled only the 32 bit version. Works flawlessly.

The 64 bit version crashed Sonar every time, so I also installed the 32 bit one and it works! Thank you for that tip!

I can confirm some crashing with Melodyne 4 Studio.  Especially if you clone an audio track with an instance of Melodyne in it.  I've also had some frightening distortion type issues at the beginning of an audio track with Melodyne.  I've seen the level meters go to +84!  It's a very LOUD click!  Didn't think anything could go past zero but it's happened.  So, yes there are some stability issues it seems with Melodyne 4.  But what's bummed me out is these guys didn't pay attention to improving the audio quality of polyphonic processing.  It still sounds "phase-shifty" on most things.  Also the splitting of clips...  mother of gawd...  software should be smart but...  I don't know if I'll ever use the sound designer and...  I'm OT now.... 

I have ceased to use my daw as I was all set to tweak the bk vox using Melodyne when I stupidly updated to 4. Now I can't. I don't know if this is a Sonar issue or not but I am cautiously optimistic that the next update will fix it.
 
I'm 32 bit btw.
 

Weird...    Melodyne 64bit has been working great for me, no crashes at all.  I updated to the 4.04 build about a week ago, but even that seems to be OK based on limited testing.   I am still on Win7 though...

I installed Melodyne 4.0.4 yesterday and was surprised to discover that it now requires internet connectivity which my DAW does not have.  I contacted Celemony and they said go on-line as no off-line registration option exists. I would like to roll back to the previous version.  Has anyone done this successfully and if so could you share the process?
thanks!
Win7 & SPlat (latest build) here

Celemony must be really backed up with tech support for this new release.  going on 3 weeks now

I consistently experience the crash described in this thread. On my current project, Sonar crashes whenever I create a new Region FX with Melodyne 4.00.0401. I'm running Windows 10 with 64 bit plugins end to end. I've been in touch with Celemony and sent them a minidump file on 3/24/2016, but no response yet. (A few days before, they promptly responded to a license problem I had. Turned out to be user error trying to fall back to Essentials 2.)
 
I never had a problem with Melodyne Essentials 2. I upgraded to 4, then used the temporary demo license for Editor, then fell back to Essentials. I didn't use the system for several weeks after that, and when I resumed, the crashes started. Existing Melodyne Region FX work fine, and I can open and edit them--I just can't create a new region.
 
Oh, and to add insult to injury, somewhere along the line, all my edits to Melodyne regions were lost. The regions still existed, but all pitch and time corrections vanished, and I had to reapply them.

I remember the Essential upgrade from 2 to 4 explicitly warned me that if I do this there is no going back. As usual I thought "Pfft, what could go wrong..........."
 
Of all the emoticons available here, why is there no facepalm.gif like on gearslutz?
 

Ok: Updated to Melo 4.04 and March early access version.
 
On the offending lead vocal track in a big "done" project with a few splits here and there, creating a melodyne region crashes Sonar after initializing region. No matter where in the lead vocal track I make a region. If I bounce the lead vocal track to a single clip then I can again create regions without crashing. I copied the lead vocal track edits and all to a new file with the intent of sending it to support, but here, even though the splits and edits are there, Sonar can now create the melodyne region without crashing so I don't know what to think. I am on 32 bit Windows / Sonar so memory is an issue but many of you in this thread are on 64bit with all your process space have had this issue presumably since melo 4. I can tell you that I don't remember this being an issue with melo 2.