If Audiobook Builder tells you “The iTunes Library framework isn’t available” when you ask it to add the iTunes selection, you only need to update to iTunes 12.4.1 to get back in business. iTunes 12.4 accidentally left out support for 32-bit applications, like Audiobook Builder, but iTunes 12.4.1 restored that support. To get the update, open iTunes, go to the iTunes menu, and click the Check for Updates… menu item.
Going forward, the next version of Audiobook Builder will prevent this from happening again. We’ll launch a custom, 64-bit helper application that Audiobook Builder silently communicates with in the background, retrieving track locations from iTunes as needed. You won’t even know it’s there – and Audiobook Builder will work the same as always.
Feel free to send a message to support@splasm.com if you need any additional details. We’ll be happy to provide them!