qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.

SuDeEpT

Hi Concerned,

I am trying to launch cyusb_linux application, i am facing this below error. How do we resolve these.

***root@BDAKA053:/home/tester/Sudeept_WS/cyusb_linux_offline# cyusb_linux
qt.qpa.xcb: could not connect to display :0.0
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.***

Aborted (core dumped)

Thanks in advance.

Regards,
Sudeept

Axel Spoerl

qt.qpa.xcb: could not connect to display :0.0

That's where it goes wrong. The application can't connect to the X server. Reasons can be manyfold: X server not running at all, application being started from a terminal that has no access to it, environment variable DISPLAY pointing to the wrong terminal :0.0.
It's a local configuration issue, not related to Qt.

JonB

@SuDeEpT
As @Axel-Spoerl has written. The issue is solely that your application cannot access any X display.

I notice that your prompt shows you are trying run as root. It is common for root not to have access to the display. Have you tried to run your application logged in as a normal user and from a terminal where you invoke it just as that normal user?

SuDeEpT

@JonB

I tried with tester user (without super privileges), still the same issue seen. Any other pointer for solving the issue?

Thanks,
Sudeept

SuDeEpT

@Axel-Spoerl @JonB ,

For your info, i am launching GUI application through putty session, is that reason x server not starting automatically.

hskoglund

Found this on StackOverflow, maybe it helps:
...
In Putty, under SSH>X11, you need to make sure that you "Enable X forwarding" and set the display to the server "X display location := localhost:0". You can also check that everything is working by doing "echo $DISPLAY" once you log in through SSH. If the graphics is being forward correctly to the Xserver, then it should read the variable DISPLAY should have the value :10 or :0. The values can vary somewhat, depending on how many X sessions you have running: https://unix.stackexchange.com/questions/10121/open-a-window-on-a-remote-x-display-why-cannot-open-display

Axel Spoerl

@SuDeEpT

For your info, i am launching GUI application through putty session, is that reason x server not starting automatically.

That's important information, to be mentioned at the beginning rather than at the end...