X11 forwarding request failed on chael 0

From a linux client I'd like to use X11 forwarding in a CentOS 7 server.

I've followed many advices found in Inteet:

1) Checked that the xauth package is installed. 2) The /etc/ssh/sshd_config file contains the following lines:

AddressFamily   inet
X11Forwarding   yes
X11UseLocalhost no

3) I've restarted the sshd daemon:

systemctl restart sshd

but when ruing from the client this command:

ssh -X [email protected] xeyes

I get this error message:

X11 forwarding request failed on chael 0
Error: Can't open display:

What else am I missing?