X11-forwarding not supported by server (CentOS 7)

Question

i use MobaXterm SSH Client to use Terminal windows on a CentOS 7 Linux VM. When i logged in, following message displayed:

X11-forwarding : ✘ (disabled or not supported by server)

Doings:

uncommented Configuration in /etc/ssh/sshd_config:

X11Forwarding yes (in /etc/ssh/ssh_config too)

AddressFamily inet

AllowTcpForwarding yes

X11Forwarding yes

X11DisplayOffset 10

X11UseLocalhost yes

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xorg-x11-xauth installed

xauth installed

xorg-xauth installed

My $DISPLAY is still empty

So where is the Problem for X11 forwarding on my Server? My configuration Files looks fine.