Rustdesk - Unsupported display server tty, x11 expected

Hi Folks,
I’m just getting back into Linux. Since I’m using an older RPi 3 Model B+ (aarch64) device, I thought I would try/use dietpi OS. I want to place the device at a remote site for remote access.

The plan is to use Rustdesk on the raspberry pi device for local network access. I keep getting an “Unsupported display server tty, x11 expected” on the Rustdesk screen. I have poked around, but no joy. Can someone point me in the right direction??

System:
Host: DietPi
Kernel: 6.12.75+rpt-rpi-v8
arch: aarch64 bits: 64
Desktop: Xfce v: 4.20.1
Distro: Debian GNU/Linux 13 (trixie)
RPi 3 Model B+ (aarch64)

Rustdesk installed, Version: 1.4.6, Build date: 2026-03-05 05:28

Maybe something @StephanStS can help with

So XFCE is running and when you start the client software you see this message?
And can you share the output of

 echo $XDG_SESSION_TYPE

edit #1:

you mean this?

I could connect to the machine just fine, despite this error message:

But XDG_SESSION_TYPE is set to tty despite the fact that XFCE is running, maybe this is why we see the message but it’s working anyways.
I guess it#s still tty because we start it from console via startx. And Rustdesk works because there is a display available.

@MichaIng what do you think?

edit #2:

When setting autostart to Desktop → LightDM login mask, XDG_SESSION_TYPE is set to x11 tho and the message does not appear.

Now to see if I can get the regular users to login automatically, startx and make sure Rustdesk start. Then this will be useful. So far, I’m enjoying Dietpi.

You can use dietpi-autostart to directly log into the desktop environment.

For app autostart in XFCE see

WOW, I thought I had totally messed it up. Took a few times to get the autologin/autostart to work. The biggest key was to add this command via cli: sudo systemctl enable rustdesk
The cool thing, even the client does not throw the “unsupported error” anymore (either one).
So, now it appears to work!!
Thanks for pointing me in the right direction!!