Seems the same problem I've had. Solution was: /etc/NetworkManager/NetworkManager.conf
Content of the file: [main] plugins=ifupdown,keyfile [ifupdown] *managed=true* After upgrade from Wheezy to Jessie managed=false; set it to TRUE and Network-connection will not fail anymore In my <control-bar> at the bottom of the screen, i have applet networkmanagement installed - before correcting above mentioned file, it always showed that NO network-connection is available. A workaround was "ifup eth0" in a console-window; that caused software-management (in systemsettings) not to fail in case of beeing 'offline'. Greetings Herbert Der Horizont vieler Menschen ist ein Kreis mit Radius Null - und das nennen sie ihren Standpunkt
