Error when using "sudo Nautilus", how do I solve it?

Question

Here is the terminal log.

http://pastebin.com/xTEK13B7

How do I fix it? What does it do? Is it safe or okay?

Answer 1

Nautilus is a graphical application so you ought to use gksudo instead :

gksudo nautilus

When you want to do graphical things with high prilivegies, gksudo and gksu are much more convinient than sudo and su.

Answer 2

It is an uncritical message; nautilus should run normally; for reference see this report at launchpad.

Answer 3

In Ubuntu 18.04 gksudo is gone.

Instead, try:

sudo -H nautilus