When attempting to launch system-config-users from command line, I get the following warning, and the tool does not open. I'm using CentOS 7 with Mate 1.8.1.
WARNING **: Error enumerating actions: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.PolicyKit1 was not provided by any .service files
Error checking for authorization org.freedesktop.policykit.exec: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.PolicyKit1 was not provided by any .service files
yum list polkit*
Installed Packages
polkit.x86_64 0.112-5.el7 @anaconda
polkit-devel.x86_64 0.112-5.el7 @base
polkit-docs.noarch 0.112-5.el7 @base
polkit-gnome.x86_64 0.105-6.el7 @epel
polkit-pkla-compat.x86_64 0.1-4.el7 @anaconda
What is missing from my system to cause this error?