I just tried to use Melodyne and it will only work in "Play" mode.
 
The Activation Assistant opens and says I don't have an internet connection. Yeah, it's slow but it's there, so what gives???
 
I click on the "License" link to activate it and nothing happens.
 
I went ahead and registered the S/N on Celemony's website... using the internet connection Melodyne says is not there.
 
I sent Celemony an email so I'm hopeful to get help there.
 
I had a similar issue with Addictive Drums. Why is there no heads up on the song and dance required to use these add-ons?

Celemony will likely help, they were pretty helpful to me.
 
Unfortunately, most companies don't take Cakewalk's sensible attitude towards copyprotection/DRM and Cakewalk can't do anything. So the included addons have stupid DRM sometimes. Nothing to be done.

Funny no one here is having this issue. Fortunately I had the same issue in January with their Trial program and saved the steps needed to get it working.
 
It is a Windows issue apparently very few people have.

Everyone is pitch perfect.

I might of guessed! I don't have perfect pitch (if there really is such a thing) But then I never use it for that. I'm more of a 'play or sing it in one key and then decide I want it in another key' kind of guy. Not something I use very often but when one tool doesn't work to my liking I like the options on hand to work since I paid for them.
 
Case in point is a guitar track I made a few years ago but now want it to be a key higher. I could never replay it as good now as I did then so the easy way out is to shift it up. Then there's the occasional word or line sung in the wrong key that an overdub wouldn't fix.