Sporadic problem here, often the most frustrating kind. I'm working on a tune where I had to fix around 6 slightly off-key notes from my vocalist, so I made 6 different Melodyne Region FX sections. Problem is, 2 of them have very audible pops as the Region FX ends; you can actually see where it occurs as the Region FX section is shaded relative to the rest of the track. When I bypass the Region FX the pop disappears, when I render the Region FX the pop remains. Short of redoing that particular phrase, and intentionally ending the Region FX in an area where I can cut out the pop without affecting another word, does anyone have any thoughts or suggestions? Thanks in advance!

Perhaps you can zoom way in on the popped part (tiny) and split it into a new note, then use the amplitude tool to bring the value of just the pop way down maybe even to zero...but the pop shouldn't be there in the first place.
 
Can you copy the original vocal to a new track, transfer it to a new Melodyne instance and see if it renders the pop with it?  Maybe your first try had a glitch in it somehow.
 
A screenshot would be helpful.  And which version of Melodyne do you have?  Studio?  Editor?

Not sure if this is the same situation but I discovered through our community that many will clone the track they auto corrected and archive 1 so they have the original. Then they will render the active track which has resolved many issues I have had in the past with pops and wierd artifacts. I also discovered in my experience it was sometimes propritory to the audio interface. My presonus studio system seemed to have more oddities than my focusrite mobile system however it could be propritory to the computer hardware systems themselves.

Cant say I have run in to this before, however Vocals are know for producing such artifacts.
It could be a matter of the algorithm used but I suspect something in the original vocal track that is not appearing until processing takes place. Are the trouble spots on syllables ? "P" / "K" / "S" sounds ?
As mentioned earlier, make a copy and reduce the section with automation.

Thank for the feedback! I'll try some of these suggestions a little later when I'm at the DAW and report back. FWIW, in using the version of Melodyne that comes with Splat, I think Editor.

mrpippy2
Thank for the feedback! I'll try some of these suggestions a little later when I'm at the DAW and report back. FWIW, in using the version of Melodyne that comes with Splat, I think Editor.

Essential comes with Splat.

Then Essential it is. I knew it started with an E...

If it happens at the end because there's signal there, it's probably due to a level difference. If it happens where there's no signal, a short fadeout of 5-7 ms or so, possibly coupled with a truncation, should take care of it.

Does the pop happen when you get to the end in Melodyne and it loops back to the beginning?

Easy fix, just deleted that particular Region FX and reapplied it using a slightly different end point. No click anymore. No idea why it was there during the previous application but it's all good now! Thanks to everyone for the advice and input.