software-properties-gtk не открывается

Я ответил на все вопросы по этому предмету, но ни один из них не дал мне решения. Может ли кто-нибудь мне помочь?

Ubuntu 19.04 вывод software-properties-gtk:

wim@PC-kamer:~$ software-properties-gtk
ERROR:dbus.proxies:Introspect error on :1.209:/: dbus.exceptions.DBusException: org.freedesktop.DBus.Error.NoReply: Message recipient disconnected from message bus without replying
Traceback (most recent call last):

 File "/usr/bin/software-properties-gtk", line 100, in <module>
    app = SoftwarePropertiesGtk(datadir=options.data_dir, options=options, file=file)

File "/usr/lib/python3/dist-packages/softwareproperties/gtk/SoftwarePropertiesGtk.py", line 172, in __init__
    self.backend.Reload();

 File "/usr/lib/python3/dist-packages/dbus/proxies.py", line 70, in __call__
    return self._proxy_method(*args, **keywords)

 File "/usr/lib/python3/dist-packages/dbus/proxies.py", line 145, in __call__
    **keywords)

File "/usr/lib/python3/dist-packages/dbus/connection.py", line 651, in call_blocking
    message, timeout)
and tried 
dbus.exceptions.DBusException: org.freedesktop.DBus.Error.ServiceUnknown: The name :1.209 was not provided by any .service files