TypeError: 'module' object is not callable when running system-config-services

Issue

• When running system-config-services, the following error message is output.

Traceback (most recent call last):
  File "/usr/sbin/system-config-services", line 1040, in <module>
    GUI(use_dbus=use_dbus).run()
  File "/usr/sbin/system-config-services", line 966, in __init__
    (serviceherders, services) = self.dbus_init()
  File "/usr/sbin/system-config-services", line 996, in dbus_init
    import scservices.dbus.proxy.serviceherders as serviceherders
  File "/usr/lib/python2.6/site-packages/scservices/dbus/proxy/serviceherders.py", line 28, in <module>
    from scservices.dbus.proxy.services import DBusSysVServiceProxy, \
  File "/usr/lib/python2.6/site-packages/scservices/dbus/proxy/services.py", line 24, in <module>
    from scservices.dbus.proxy.servicesinfo import DBusServiceInfoProxy, \
  File "/usr/lib/python2.6/site-packages/scservices/dbus/proxy/servicesinfo.py", line 44, in <module>
    class DBusSysVServiceInfoProxy(DBusServiceInfoProxy):
  File "/usr/lib/python2.6/site-packages/scservices/dbus/proxy/servicesinfo.py", line 52, in DBusSysVServiceInfoProxy
    @polkit.enable_proxy
  File "/usr/lib/python2.6/site-packages/slip/dbus/polkit.py", line 161, in enable_proxy
    return decorator(_enable_proxy, func)
TypeError: 'module' object is not callable

• There is a similar article but details are a bit different from this.