Today, I found out that my version of Storyist for my Mac could not generate a Kindle ebook (.mobi). Turns out I needed to replace my 32-bit KindleGen with 64-bit. And it turns out that Amazon no longer has a direct link to KindleGen. So I googled a bit, and found out how to get the KindleGen in Kindle Publisher. Here is what I did.
Download and install the latest Kindle Previewer from Amazon. https://www.amazon.com/gp/feature.html?ie=UTF8&docId=1000765261
In the Applications folder, control-click the Kindle Previewer 3.app and select Open Package Contents from the pop-up menu.
You will see a folder called Contents. Copy it.
In your Applications folder, create a folder called “Kindle Previewer 3 app contents”. (Or whatever you like, but this name tells it like it is. And no quotes in the folder name, of course.)
Paste the Contents folder into the “Kindle Previewer 3 app contents” folder. (You can find kindlegen in there if you like, I have the path in the next step.)
Go through the process of exporting a Kindle (mobi) file in Storyist. When you get to Step 3: Enter Kindle options, change your KindleGen Location to:
/Applications/Kindle Previewer 3 app contents/lib/fc/bin/kindlegen
Click Next to continue exporting your Kindle file.