In the server list when adding a new server ("Add Server" button) or editing an existing one ("Edit" button), clicking on the text fields or trying to write in them when they have focus (press TAB key) closes the screen.
MC-166562 Cannot Add Servers
MC-166651 Can't edit server info
MC-166710 Clicking Server Address box closes menu
MC-122135 Several GUIs are not closed when pressing ESC
MC-151412 "Edit Server Info" window does not focus "Server Name" text field automatically