Open fcitx configuration but no input method shows

I was trying to install sogoupinyin to type chinese in my ubuntu 16.04.

After installation, when I type fcitx-config-gtk3 in the terminal to open the fcitx input method configuration, the following warning messages pop out:

(fcitx-config-gtk3:2725): GLib-GIO-CRITICAL **: 
g_dbus_connection_call_internal: assertion 'G_IS_DBUS_CONNECTION 
(connection)' failed

** (fcitx-config-gtk3:2725): WARNING **: 
GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name 
org.fcitx.Fcitx-0 was not provided by any .service files

(fcitx-config-gtk3:2725): GLib-GIO-CRITICAL **: 
g_dbus_connection_call_internal: assertion 'G_IS_DBUS_CONNECTION 
(connection)' failed

** (fcitx-config-gtk3:2725): WARNING **: 
GDBus.Error:org.freedesktop.DBus.Error.NameHasNoOwner: Name 
"org.fcitx.Fcitx-0" does not exist

Although the input method configuration still opens and there is sogou cloud pinyin in the addon tab, there is not any input method shown in the input method tab. Does anyone know how to do with it?

Thanks!