The customer is running P/I Output Manager. In the user interface, the are missing one of the Input Clients (PDF-IN)
The size of the window for the Input Clients was hiding the client icon lower in the window.
1. Resize the window so all the client icons are shown, or scroll down within the smaller window, or
2. Switch from Icon View to Text View so more clients can be displayed within the same amount of window real estate.
UPDATED: August 14, 2017