Trying to edit a new novel is turning into a real problem thanks to Amazon's seeming inability to update their Kindle Previewer for El Capitan. This is a strange situation for a multi-million dollar company - they've had many months access to the beta. I wonder how other people are getting around this?
I did try tinkering with the package contents and editing Java commands in the launcher file but it still fails to run. Honestly, it's pretty embarrassing that anyone should have to resort to this.