Apple had apparently adopted a rather arrogant policy in which they were compelling iPhoto users to make the transition to Photos and to the iCloud by locking iPhoto users out of using the latest iteration of iPhoto anymore. When Apple executives released the new application called Photos in the spring of 2015, they left open a very short window in which iPhoto fans could download and install version 9.6.1 of iPhoto, which is the end of the line for that application.
