Woop something I know the answer to!
Go back into the Editmesh options and modify, now move some of your points so they're further away from the image.
When your image is a little larger than the bounds you've created your mesh at, things get a bit crazy in spine, even if just a small corner pokes out of the mesh bounds you'll get those invisible areas. I recently had this and fixed it that way, tested again and indeed that was the issue.
Additionally, from this shot here, it seems like you're going a bit overboard with this image, a wiser choice (requiring dramatically less points) would be to have things like the eyes, nose and mouth be seperate images that you overlay ontop of the empty face.
