Ubuntu 16.04 (xenial) amd64
$ sudo journalctl -b -p err set 28 22:07:52 system NetworkManager[927]: nm_device_get_device_type: assertion 'NM_IS_DEVICE (self)' failed
Ubuntu 16.04 (xenial) amd64
$ sudo journalctl -b -p err 927]: nm_device_ get_device_ type: assertion 'NM_IS_DEVICE (self)' failed
set 28 22:07:52 system NetworkManager[