Q:

sudo nautilus error in 16.04

I'm trying to set up localhost with these instructions
Now at step 11 I'm supposed to open nautilus in terminal but whatever I do it throws some error at me. 
I tried reinstall and update nautilus with no luck; the same errors appear after using sudo nautilus.
This is what the error looks like.
(nautilus:4594): GLib-GIO-CRITICAL **: g_dbus_interface_skeleton_unexport: assertion 'interface_->priv->connections != NULL' failed
(nautilus:4594): GLib-GIO-CRITICAL **: g_dbus_interface_skeleton_unexport: assertion 'interface_->priv->connections != NULL' failed
(nautilus:4594): Gtk-CRITICAL **: gtk_icon_theme_get_for_screen: assertion 'GDK_IS_SCREEN (screen)' failed
(nautilus:4594): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(nautilus:4594): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion 'G_TYPE_CHECK_INSTANCE (instance)' failed

I'm new to Linux and Ubuntu. I tried to google for the errors but without luck.
In Ubuntu I only replaced gnome network with wicd network manager
thanks in advance for any suggestions or help 
Ivo 

A:

These are not errors. These are warnings and all warnings are to be ignored. 
With that said, you should use sudo -i to run gtk applications with sudo.
sudo -i nautilus

These warnings are normal and are to be ignored safely. 
Although a fix is not necessary, there is a workaround.
The only work around requires you install the development files:
sudo apt-get update
sudo apt-get install libgdk-pixbuf2.0-dev
sudo gdk-pixbuf-query-loaders --update-cache
sudo killall nautilus

That should take care of most of the warnings. 
If you don't like to see output in the terminal after running the command, you can use the nohup command like so:
nohup sudo -i nautilus

or
nohup sudo -i nautilus &

Again, in the future, you can ignore warnings like these unless there is a problem running the application.

