gparted won't start under ubuntu 17.10 [duplicate]

Solution 1:

It is known bug of Wayland (I read it as "high security is better than user comfort" and I do not support developer's logic).
It was already reported (see bug 1652282).
Other root applications are broken on Wayland too (see bug 1713313 and bug 1713311 ).

You should switch to "Ubuntu on Xorg" session for such applications.

For applications which use su-to-root and pkexec you may want to add this code to /etc/xdg/autostart/xhost.desktop (see my comment at launchpad) at your own risk with command below:

cat <<EOF | sudo tee /etc/xdg/autostart/xhost.desktop
[Desktop Entry]
Name=xhost
Comment=Fix graphical root applications
Exec="xhost +si:localuser:root"
Terminal=false
Type=Application
EOF

If you do not want permanent solution, you may use @ravery's method:

just type xhost +si:localuser:root in the terminal before launching gparted