I had direct Ethernet connection without a router working in Ubuntu 16.04 for SSH as explained at: https://raspberrypi.stackexchange.com/a/53823/33424
But when I tested again 17.04, set "Shared to other computers", and select that connection, an error dialog appears:
Connection activation failed.
(0) Active connection could not be attached to the device
The only thread I could find was: https://askubuntu.com/questions/856007/failed-to-add-activate-connection but "All users may connect to this network" is already checked.
RPI 2 + Raspbian Jessie 2016-05-27 and 2017-04-10.