# Error launching Slicer on Rocky 9 linux: \`Could not load the Qt platform plugin "xcb" in "" even though it was found\`

**URL:** <https://discourse.slicer.org/t/error-launching-slicer-on-rocky-9-linux-could-not-load-the-qt-platform-plugin-xcb-in-even-though-it-was-found/36765>\
**Category:** Support\
**Created:** [June 13, 2024, 7:10pm UTC](https://discourse.slicer.org/t/error-launching-slicer-on-rocky-9-linux-could-not-load-the-qt-platform-plugin-xcb-in-even-though-it-was-found/36765 "2024-06-13T19:10:36Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![113992](https://avatars.discourse-cdn.com/v4/letter/1/5fc32e/32.png) [@113992](https://discourse.slicer.org/u/113992)\
**Post date:** [June 13, 2024, 7:10pm UTC](https://discourse.slicer.org/t/error-launching-slicer-on-rocky-9-linux-could-not-load-the-qt-platform-plugin-xcb-in-even-though-it-was-found/36765/1 "2024-06-13T19:10:36Z")

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Hello, I am having some issues when launching the Slicer program. This is the output with export QT\_DEBUG\_PLUGINS=1. I am on Rocky Linux 9:

> QFactoryLoader::QFactoryLoader() ignoring “com.trolltech.Qt.QInputContextFactoryInterface” since plugins are disabled in static builds  
> QFactoryLoader::QFactoryLoader() ignoring “com.trolltech.Qt.QStyleFactoryInterface” since plugins are disabled in static builds  
> QFactoryLoader::QFactoryLoader() ignoring “com.trolltech.Qt.QImageIOHandlerFactoryInterface” since plugins are disabled in static builds  
> QFactoryLoader::QFactoryLoader() checking directory path “/opt/3Dslicer/5.6.2/lib/QtPlugins/platforms” …  
> QFactoryLoader::QFactoryLoader() looking at “/opt/3Dslicer/5.6.2/lib/QtPlugins/platforms/libqxcb.so”  
> Found metadata in lib /opt/3Dslicer/5.6.2/lib/QtPlugins/platforms/libqxcb.so, metadata=  
> {  
> “IID”: “org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3”,  
> “MetaData”: {  
> “Keys”: [  
> “xcb”  
> ]  
> },  
> “archreq”: 0,  
> “className”: “QXcbIntegrationPlugin”,  
> “debug”: false,  
> “version”: 331520  
> }
> 
> Got keys from plugin meta data (“xcb”)  
> QFactoryLoader::QFactoryLoader() checking directory path “/opt/3Dslicer/5.6.2/bin/platforms” …  
> Cannot load library /opt/3Dslicer/5.6.2/lib/QtPlugins/platforms/libqxcb.so: (libxcb-icccm.so.4: cannot open shared object file: No such file or directory)  
> QLibraryPrivate::loadPlugin failed on “/opt/3Dslicer/5.6.2/lib/QtPlugins/platforms/libqxcb.so” : “Cannot load library /opt/3Dslicer/5.6.2/lib/QtPlugins/platforms/libqxcb.so: (libxcb-icccm.so.4: cannot open shared object file: No such file or directory)”  
> 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.
> 
> error: [/opt/3Dslicer/5.6.2/bin/SlicerApp-real] exit abnormally - Report the problem.

I have seen this error mentioned on Ubuntu/Debian but not Rocky and admittedly I am a little stumped.

I yum installed the prerequisites: mesa-libGLU libnsl.

Am I missing an additional list of dependencies for Rocky 9?

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**Author:** ![RafaelPalomar](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/rafaelpalomar/32/1436_2.png) [@RafaelPalomar](https://discourse.slicer.org/u/RafaelPalomar)\
**Post date:** [June 13, 2024, 7:28pm UTC](https://discourse.slicer.org/t/error-launching-slicer-on-rocky-9-linux-could-not-load-the-qt-platform-plugin-xcb-in-even-though-it-was-found/36765/2 "2024-06-13T19:28:51Z")

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Hello. Yesterday, I went through some Linux distributions and updated the documentation in this PR (not yet merged): [DOC: Update Linux documentation by RafaelPalomar · Pull Request #7798 · Slicer/Slicer · GitHub](https://github.com/Slicer/Slicer/pull/7798). Rocky is not in the list, but maybe some of the other distros can be used as inspiration for the dependencies.