Deconz-Gui Service cannot be started

General
1

Hey guys,
I have a Conbee2 stick connected to Raspberry Pi 3b, running homebridge on it and the conbee plugin. Everything works fine, also the deconz web server, except 1 problem:

I have 2 Zigbee devices, which don’t behave properly and I want to see the ZigBee Topology View to check their connections.
The installation was headless before, I installed GUI (GDM3) after deconz.

Now unfortunatelly I cannot start the deconz-GUI.
I disabled and stopped deconz and enabled and started deconz-GUI.
But when I try to start the application with mouse-click, nothing happens.

In the SSH session, when checking for deconz-gui “status” it says the following:

deconz fehler2
deconz fehler21309×519 163 KB

i@homebridge:~ $ sudo systemctl start deconz-gui
pi@homebridge:~ $ systemctl status deconz-gui
● deconz-gui.service - deCONZ: ZigBee gateway – GUI/REST API
Loaded: loaded (/lib/systemd/system/deconz-gui.service; disabled; preset: enabled)
Active: activating (auto-restart) (Result: signal) since Tue 2025-07-22 13:05:56 CEST; 4s ago
Process: 11264 ExecStart=/usr/bin/deCONZ --http-port=8091 (code=killed, signal=ABRT)
Main PID: 11264 (code=killed, signal=ABRT)
CPU: 172ms

Jul 22 13:05:56 homebridge deCONZ[11264]: qt.qpa.xcb: could not connect to display :0
Jul 22 13:05:56 homebridge deCONZ[11264]: qt.qpa.plugin: Could not load the Qt platform plugin “xcb” in >
Jul 22 13:05:56 homebridge deCONZ[11264]: This application failed to start because no Qt platform plugin>
Jul 22 13:05:56 homebridge deCONZ[11264]: Available platform plugins are: eglfs, linuxfb, minimal, minim>
Jul 22 13:05:56 homebridge systemd[1]: deconz-gui.service: Main process exited, code=killed, status=6/AB>
Jul 22 13:05:56 homebridge systemd[1]: deconz-gui.service: Failed with result ‘signal’.
lines 1-13/13 (END)…skipping…
● deconz-gui.service - deCONZ: ZigBee gateway – GUI/REST API
Loaded: loaded (/lib/systemd/system/deconz-gui.service; disabled; preset: enabled)
Active: activating (auto-restart) (Result: signal) since Tue 2025-07-22 13:05:56 CEST; 4s ago
Process: 11264 ExecStart=/usr/bin/deCONZ --http-port=8091 (code=killed, signal=ABRT)
Main PID: 11264 (code=killed, signal=ABRT)
CPU: 172ms

Jul 22 13:05:56 homebridge deCONZ[11264]: qt.qpa.xcb: could not connect to display :0
Jul 22 13:05:56 homebridge deCONZ[11264]: qt.qpa.plugin: Could not load the Qt platform plugin “xcb” in “” even though it was >
Jul 22 13:05:56 homebridge deCONZ[11264]: This application failed to start because no Qt platform plugin could be initialized.>
Jul 22 13:05:56 homebridge deCONZ[11264]: Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc,>
Jul 22 13:05:56 homebridge systemd[1]: deconz-gui.service: Main process exited, code=killed, status=6/ABRT
Jul 22 13:05:56 homebridge systemd[1]: deconz-gui.service: Failed with result ‘signal’.

Any advice?

2

It seems the Xorg or Wayland session isn’t running.
Can you start other GUI applications like a GUI terminal?

3

Thanks for your reply.
I installed xorg already. Do I need Wayland additionally?
What do you mean with GUI Terminal? I can boot into GUI and login, open network settings, or the GUI for VNC Server (even though it does not work either, but the GUI opens, for example.)

deconz-gui error
deconz-gui error1497×447 40.8 KB

4

If you already have Xorg you don’t need to install Wayland.
What I meant is is the desktop environment running, e.g. seeing graphical widgets?

Usually from there you can launch deCONZ via the applications menu in Raspberry Pi OS manuall, while deconz and deconz-gui systemd services are stopped.

5

okay. Yes, Xorg is installed and desktop environment is running. I can see graphical widgets and open settings, help-menu, X11 VNC Server. Deconz Widget is visible, but nothing happens, after it is clicked.