dbus-user-session software package provides simple interprocess messaging system (systemd --user integration), you can install in your Ubuntu 16.04 LTS (Xenial Xerus) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install dbus-user-session
dbus-user-session is installed in your system.
Make ensure the dbus-user-session package were installed using the commands given below,
$ sudo dpkg-query -l | grep dbus-user-session *
You will get with dbus-user-session package name, version, architecture and description in a table
| Distro | Ubuntu 16 04 lts xenial xerus |
| Section | Administration Utilities |
| Package | dbus-user-session |
| Version | 1.10.6-1ubuntu3.1 |
| Description | simple interprocess messaging system (systemd --user integration) |
| Sub Section | admin |