There's a lot of variables in this problem. Is it the project size, track count, too many plugs, one bad plug, it could be almost anything. I'm wondering if a look at the Melodyne forum could provide clues regarding things that Melodyne doesn't get along with. Then you could at least check to see if you are using the bad actor.
You don't say if the crash is as soon as you load Melodyne, or if it crashes during editing. So many things to consider, and I wish I had more to offer.