/usr/bin/xauth: file /home/user/.Xauthority does not exist :
.Xauthority exist
under /root/
Do I have
to install a X server on the computer-server SSH ?
x11-apps, x11-common, xbitmaps :
are installed.
Why the
DISPLAY regardless of the number is never accepted ? :
Because we concluded that
your setup is broken and you have to repair it.
What do you mean by "my setup is broken" ?
(which setup ?).