The Inactivity Window is a security feature added to select builds of Gen 12 of MacPractice. It has also been added to the corresponding MacPractice iPad Apps. Currently this feature is only present in 12.11.2 and up.
The Inactivity Window functions as a privacy shield if you do not interact with the device for longer than five minutes. Once those five minutes have expired, the device will present a login window with a message indicating that the user session has expired, and they will need to log back in with their MacPractice username and password to continue using MacPractice/MP Apps.
In MacPractice, this is how the Inactivity Window will appear, bearing a strong resemblance to a stripped down login screen.
On our iPad Apps, the Inactivity Window will appear like so: