I am running Ubuntu 18.04 and although both Ubuntu Software and Software Updater are present and working fine, Software & Updates is missing from Applications, and pressing the Settings button on the Updater asks for my password and then shows a busy cursor for a few seconds and then nothing. Running software-properties-gtk
results in:
LSB codename: 'bionic'.
This codename isn't currently supported.
Please check your LSB information with "lsb_release -a".
Running lsb_release -a
results in:
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 18.04.1 LTS
Release: 18.04
Codename: bionic
I have noticed a new app in the Application Menu called Software Sources. This program does the same thing as clicking the Settings button in Updater.