Comment 8 for bug 1449748

This is still a bug in Ubuntu 16.04. In my case, it comes from running a gui (synaptic package manager) as root inside a tiger vncserver session. It runs fine in the last vncserver it was run in, but from the real desktop console it conks out with the following error:

```root@ubuntu1604-p6720f:~# synaptic
No protocol specified
Failed to connect to Mir: Failed to connect to server socket: No such file or directory
Unable to init server: Could not connect: Connection refused

(synaptic:23495): Gtk-WARNING **: cannot open display: :1
root@ubuntu1604-p6720f:~# DISPLAY=:0 synaptic
No protocol specified
Failed to connect to Mir: Failed to connect to server socket: No such file or directory
Unable to init server: Could not connect: Connection refused

(synaptic:23624): Gtk-WARNING **: cannot open display: :0
root@ubuntu1604-p6720f:~# ```

As shown, even if I specify the exact display to open, it refuses to run in the main desktop. For whatever reason, Mir isn't running. I have no clue what that is. It also says "No protocol specified" -- is there a way to work around it by specifying a protocol?