There is no way to get the Book menu tree plugin. Further more some text are swapped.
Fix texts to help people place the correct widget.
Add plugin : plugins/content_types/node_context/node_book_menu.inc
User interface changes
Original report by @bomarmonk
I checked out the usual issues related to the "add content" blocks, etc. not showing up, but are there other ways to trouble shoot this? I tried uninstalling all of the panels related modules, reinstalling, and reenabling them. The book navigation block, for instance, can't be added to a panel, because it's not available in the "add content" pop-up. However, its checkbox is checked under the setting for adding it to panels and mini-panels. Any help would be appreciated.