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

[DevAlone]

For those who could face the same issue and didn't solve by reinstalling libxcb: in my case the message was the same but it was caused by apps inside lxc unabling to open display, so, try to run another GUI app like xclock.

[rrd0]

@DevAlone

qt.qpa.xcb: could not connect to display <<-- Is that the message you're talking about?

Could you explain a little better what was your problem and how did you fix it?

What is lxc? And why to run another GUI app? I really didn't understand what you did to fix this problem.

[jcren]

@twar
Hi, twar!
I met the same error as yours, and I cannot solve it after using several methods.
Can you tell me how to fix it more clearly? I'm new to geant4, so I cannot understand what you have said.
Thank you!

Best Wishes,
jcren.

[Ezzaat]

Hi
I faced this problem and I got a new version of linuxdeployqt and now that error is gone.

[NyilasLaszlo]

Hi for all!
I downloaded and extracted XnView MP version 0.96 on Arch Linux and same error happened.

Solution:
I am deleted these two files: libfreetype.so and libfreetype.so.6 .

Here is the result:

[jarvis]

Hi ,
I am facing a similar issue could you please help.

Got keys from plugin meta data ("xcb")
QFactoryLoader::QFactoryLoader() checking directory path "/usr/bin/platforms" ...
QFactoryLoader::QFactoryLoader() looking at "/usr/bin/platforms/libqeglfs.so"
Got keys from plugin meta data ("eglfs")
QFactoryLoader::QFactoryLoader() looking at "/usr/bin/platforms/libqlinuxfb.so"
Got keys from plugin meta data ("linuxfb")
QFactoryLoader::QFactoryLoader() looking at "/usr/bin/platforms/libqminimal.so"
Got keys from plugin meta data ("minimal")
QFactoryLoader::QFactoryLoader() looking at "/usr/bin/platforms/libqminimalegl.so"
Got keys from plugin meta data ("minimalegl")
QFactoryLoader::QFactoryLoader() looking at "/usr/bin/platforms/libqoffscreen.so"
Got keys from plugin meta data ("offscreen")
QFactoryLoader::QFactoryLoader() looking at "/usr/bin/platforms/libqvnc.so"
Got keys from plugin meta data ("vnc")
QFactoryLoader::QFactoryLoader() looking at "/usr/bin/platforms/libqxcb.so"
Got keys from plugin meta data ("xcb")
loaded library "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqxcb.so"
qt.qpa.xcb: could not connect to display
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "/opt/appname/libs/Qt/plugins/platforms" 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.

[SGaist]

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

QFactoryLoader::QFactoryLoader() looking at "/usr/bin/platforms/libqminimalegl.so"
Got keys from plugin meta data ("minimalegl")
QFactoryLoader::QFactoryLoader() looking at "/usr/bin/platforms/libqoffscreen.so"
Got

Hi,

Start your application with the QT_DEBUG_PLUGINS environment variable set to 1 to get more information.

[Srinivas Reddy]

I am using Qt-5.15.0, got the same problem.
More details are:
QLibraryPrivate::loadPlugin failed on "/opt/Qt/5.15.0/gcc_64/plugins/platforms/libqxcb.so" : "Cannot load library /opt/Qt/5.15.0/gcc_64/plugins/platforms/libqxcb.so: (libxcb-xinerama.so.0: cannot open shared object file: No such file or directory)"

Solved by installing the dependent package.
Command to install: sudo apt-get install libxcb-xinerama0

[JamieC]

Fresh install had the same issues reported here. Did what @Srinivas-Reddy suggested and install libxcb-xinerama0 and everything started working. Thanks!

[PabloC]

@JamieC I had the same problem, install libxcb-xinerama0 and I solved it, Thanks!

[Advig]

Tried reinstalling libxcb and worked for me as well.

[inbdz]

@Srinivas-Reddy many thanks

[Lengendary]

Thanks very much!
I spent several hours trying to solve this problem until I got here.
sudo apt-get install libxcb-xinerama0
Thanks!

[artyjeep]

@Lengendary Thank you!

[singhravi]

Hey guys,

I'm getting the same error but not able to find any reason.
I'm building this project, https://github.com/BelledonneCommunications/linphone-desktop
and getting the error,

(linphone) ➜  Packages git:(master) ./Linphone-4.5.1.AppImage 
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: xcb.

[1]    28317 abort (core dumped)  ./Linphone-4.5.1.AppImage
(linphone) ➜  Packages git:(master) ldd ~/Qt/5.12.9/gcc_64/plugins/platforms/libqxcb.so                         
	linux-vdso.so.1 (0x00007ffe12cd8000)
	libQt5XcbQpa.so.5 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libQt5XcbQpa.so.5 (0x00007f79c2a18000)
	libfontconfig.so.1 => /usr/lib/x86_64-linux-gnu/libfontconfig.so.1 (0x00007f79c27d3000)
	libfreetype.so.6 => /usr/lib/x86_64-linux-gnu/libfreetype.so.6 (0x00007f79c251f000)
	libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f79c2302000)
	libQt5Gui.so.5 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libQt5Gui.so.5 (0x00007f79c1ab3000)
	libQt5DBus.so.5 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libQt5DBus.so.5 (0x00007f79c1827000)
	libQt5Core.so.5 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libQt5Core.so.5 (0x00007f79c108c000)
	libGL.so.1 => /usr/lib/x86_64-linux-gnu/libGL.so.1 (0x00007f79c0e00000)
	libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f79c0be1000)
	libX11-xcb.so.1 => /usr/lib/x86_64-linux-gnu/libX11-xcb.so.1 (0x00007f79c09df000)
	libxcb.so.1 => /usr/lib/x86_64-linux-gnu/libxcb.so.1 (0x00007f79c07b7000)
	libXrender.so.1 => /usr/lib/x86_64-linux-gnu/libXrender.so.1 (0x00007f79c05ad000)
	libXext.so.6 => /usr/lib/x86_64-linux-gnu/libXext.so.6 (0x00007f79c039b000)
	libX11.so.6 => /usr/lib/x86_64-linux-gnu/libX11.so.6 (0x00007f79c0063000)
	libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f79bfcc5000)
	libxkbcommon-x11.so.0 => /usr/lib/x86_64-linux-gnu/libxkbcommon-x11.so.0 (0x00007f79bfabd000)
	libxkbcommon.so.0 => /usr/lib/x86_64-linux-gnu/libxkbcommon.so.0 (0x00007f79bf87e000)
	libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f79bf67a000)
	libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f79bf2f1000)
	libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f79bf0d9000)
	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f79bece8000)
	libgthread-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007f79beae6000)
	libglib-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007f79be7cf000)
	libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1 (0x00007f79be59d000)
	libpng16.so.16 => /usr/lib/x86_64-linux-gnu/libpng16.so.16 (0x00007f79be36b000)
	libdbus-1.so.3 => /lib/x86_64-linux-gnu/libdbus-1.so.3 (0x00007f79be11e000)
	libicui18n.so.56 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libicui18n.so.56 (0x00007f79bdc85000)
	libicuuc.so.56 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libicuuc.so.56 (0x00007f79bd8cd000)
	libicudata.so.56 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libicudata.so.56 (0x00007f79bbeea000)
	/lib64/ld-linux-x86-64.so.2 (0x00007f79c2fbe000)
	libGLX.so.0 => /usr/lib/x86_64-linux-gnu/libGLX.so.0 (0x00007f79bbcb9000)
	libGLdispatch.so.0 => /usr/lib/x86_64-linux-gnu/libGLdispatch.so.0 (0x00007f79bba03000)
	libXau.so.6 => /usr/lib/x86_64-linux-gnu/libXau.so.6 (0x00007f79bb7ff000)
	libXdmcp.so.6 => /usr/lib/x86_64-linux-gnu/libXdmcp.so.6 (0x00007f79bb5f9000)
	libxcb-xkb.so.1 => /usr/lib/x86_64-linux-gnu/libxcb-xkb.so.1 (0x00007f79bb3dd000)
	libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f79bb16b000)
	libsystemd.so.0 => /lib/x86_64-linux-gnu/libsystemd.so.0 (0x00007f79baee7000)
	libbsd.so.0 => /lib/x86_64-linux-gnu/libbsd.so.0 (0x00007f79bacd2000)
	librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f79baaca000)
	liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007f79ba8a4000)
	liblz4.so.1 => /usr/lib/x86_64-linux-gnu/liblz4.so.1 (0x00007f79ba688000)
	libgcrypt.so.20 => /lib/x86_64-linux-gnu/libgcrypt.so.20 (0x00007f79ba36c000)
	libgpg-error.so.0 => /lib/x86_64-linux-gnu/libgpg-error.so.0 (0x00007f79ba157000)

What could be the issue? Please suggest.
Please let me know if you need to know anything else for this.

[singhravi]

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

Hey guys,

I'm getting the same error but not able to find any reason.
I'm building this project, https://github.com/BelledonneCommunications/linphone-desktop
and getting the error,

(linphone) ➜  Packages git:(master) ./Linphone-4.5.1.AppImage 
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: xcb.

[1]    28317 abort (core dumped)  ./Linphone-4.5.1.AppImage
(linphone) ➜  Packages git:(master) ldd ~/Qt/5.12.9/gcc_64/plugins/platforms/libqxcb.so                         
	linux-vdso.so.1 (0x00007ffe12cd8000)
	libQt5XcbQpa.so.5 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libQt5XcbQpa.so.5 (0x00007f79c2a18000)
	libfontconfig.so.1 => /usr/lib/x86_64-linux-gnu/libfontconfig.so.1 (0x00007f79c27d3000)
	libfreetype.so.6 => /usr/lib/x86_64-linux-gnu/libfreetype.so.6 (0x00007f79c251f000)
	libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f79c2302000)
	libQt5Gui.so.5 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libQt5Gui.so.5 (0x00007f79c1ab3000)
	libQt5DBus.so.5 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libQt5DBus.so.5 (0x00007f79c1827000)
	libQt5Core.so.5 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libQt5Core.so.5 (0x00007f79c108c000)
	libGL.so.1 => /usr/lib/x86_64-linux-gnu/libGL.so.1 (0x00007f79c0e00000)
	libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f79c0be1000)
	libX11-xcb.so.1 => /usr/lib/x86_64-linux-gnu/libX11-xcb.so.1 (0x00007f79c09df000)
	libxcb.so.1 => /usr/lib/x86_64-linux-gnu/libxcb.so.1 (0x00007f79c07b7000)
	libXrender.so.1 => /usr/lib/x86_64-linux-gnu/libXrender.so.1 (0x00007f79c05ad000)
	libXext.so.6 => /usr/lib/x86_64-linux-gnu/libXext.so.6 (0x00007f79c039b000)
	libX11.so.6 => /usr/lib/x86_64-linux-gnu/libX11.so.6 (0x00007f79c0063000)
	libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f79bfcc5000)
	libxkbcommon-x11.so.0 => /usr/lib/x86_64-linux-gnu/libxkbcommon-x11.so.0 (0x00007f79bfabd000)
	libxkbcommon.so.0 => /usr/lib/x86_64-linux-gnu/libxkbcommon.so.0 (0x00007f79bf87e000)
	libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f79bf67a000)
	libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f79bf2f1000)
	libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f79bf0d9000)
	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f79bece8000)
	libgthread-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007f79beae6000)
	libglib-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007f79be7cf000)
	libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1 (0x00007f79be59d000)
	libpng16.so.16 => /usr/lib/x86_64-linux-gnu/libpng16.so.16 (0x00007f79be36b000)
	libdbus-1.so.3 => /lib/x86_64-linux-gnu/libdbus-1.so.3 (0x00007f79be11e000)
	libicui18n.so.56 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libicui18n.so.56 (0x00007f79bdc85000)
	libicuuc.so.56 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libicuuc.so.56 (0x00007f79bd8cd000)
	libicudata.so.56 => /home/ravi/Qt/5.12.9/gcc_64/plugins/platforms/../../lib/libicudata.so.56 (0x00007f79bbeea000)
	/lib64/ld-linux-x86-64.so.2 (0x00007f79c2fbe000)
	libGLX.so.0 => /usr/lib/x86_64-linux-gnu/libGLX.so.0 (0x00007f79bbcb9000)
	libGLdispatch.so.0 => /usr/lib/x86_64-linux-gnu/libGLdispatch.so.0 (0x00007f79bba03000)
	libXau.so.6 => /usr/lib/x86_64-linux-gnu/libXau.so.6 (0x00007f79bb7ff000)
	libXdmcp.so.6 => /usr/lib/x86_64-linux-gnu/libXdmcp.so.6 (0x00007f79bb5f9000)
	libxcb-xkb.so.1 => /usr/lib/x86_64-linux-gnu/libxcb-xkb.so.1 (0x00007f79bb3dd000)
	libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f79bb16b000)
	libsystemd.so.0 => /lib/x86_64-linux-gnu/libsystemd.so.0 (0x00007f79baee7000)
	libbsd.so.0 => /lib/x86_64-linux-gnu/libbsd.so.0 (0x00007f79bacd2000)
	librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f79baaca000)
	liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007f79ba8a4000)
	liblz4.so.1 => /usr/lib/x86_64-linux-gnu/liblz4.so.1 (0x00007f79ba688000)
	libgcrypt.so.20 => /lib/x86_64-linux-gnu/libgcrypt.so.20 (0x00007f79ba36c000)
	libgpg-error.so.0 => /lib/x86_64-linux-gnu/libgpg-error.so.0 (0x00007f79ba157000)

What could be the issue? Please suggest.
Please let me know if you need to know anything else for this.

Hey @SGaist , Can you please suggest anything for this?

[SGaist]

@singhravi run ldd on the plugin itself.

[singhravi]

@SGaist Thanks a lot for the reply!
Do you mean this? ldd ~/Qt/5.12.9/gcc_64/plugins/platforms/libqxcb.so
If yes, then I've included its output in the original comment.
Please let me know if this is not what you mean.

[SGaist]

I missed that line.

I see that you have that issue with an AppImage, does it also happen with just your binary ?

[singhravi]

@SGaist Nope. The created binary works fine.
Only the packaged Appimage gives this issue.
PS, sorry for the delay in comments as its blocking me for 600 seconds after a comment. SMH