Adobe InDesign, Versions 15.0.0 and 15.0.1
Steps:
- Open a book or an indb file, respectively, or create a book (File - New book)
-> the book is shown in the book panel without content
- Press button + ("Add documents") at the tool bar at the bottom
-> the file file selection dialog is opened with label "Add documents"
- Select an existing indd file and press button "Open"
Expected result:
-> The indd file is added to the book
Actual result:
-> The indd file is not added to the book; the file selection dialog is opened again, but selecting the file again leads not to the expected result

(Note: I am forced to rollback to version 14.0.3 because of this issue)