SUMMARY:

Each time I start kdenlive, it stops immediately.
Each time there is a colourful window with, in the lower right corner, "version 21.04.1
Then there is a very brief window with kdenlive interface (time-line, ...)
Then kdenlive stops.

Here is the bug report:

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Application: kdenlive (21.04.1)

Qt Version: 5.15.2
Frameworks Version: 5.82.0
Operating System: Linux 5.12.10-300.fc34.x86_64 x86_64
Windowing System: Wayland
Drkonqi Version: 5.21.5
Distribution: Fedora 34 (KDE Plasma)

-- Information about the crash:

The crash can be reproduced every time.

-- Backtrace:
A useful backtrace could not be generated

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This happens all the time, including after a freshly booted system without any prior application.

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I have started kdenlive from a terminal and here is the output of the command:

$ kdenlive
No LADSPA plugins were found!

Check your LADSPA_PATH environment variable.
Invalid metadata for "telecide"
Failed to parse "telecide"
Invalid metadata for "avcolour_space"
Failed to parse "avcolour_space"
Invalid metadata for "avcolor_space"
Failed to parse "avcolor_space"
Invalid metadata for "avdeinterlace"
Failed to parse "avdeinterlace"
Invalid metadata for "swscale"
Failed to parse "swscale"
Invalid metadata for "swresample"
Failed to parse "swresample"
Invalid metadata for "glsl.manager"
Failed to parse "glsl.manager"
Invalid metadata for "movit.convert"
Failed to parse "movit.convert"
Invalid metadata for "movit.crop"
Failed to parse "movit.crop"
Invalid metadata for "movit.resample"
Failed to parse "movit.resample"
Invalid metadata for "movit.resize"
Failed to parse "movit.resize"
Invalid metadata for "jack"
Failed to parse "jack"
Invalid metadata for "audiochannels"
Failed to parse "audiochannels"
Invalid metadata for "audioconvert"
Failed to parse "audioconvert"
Invalid metadata for "data_feed"
Failed to parse "data_feed"
Invalid metadata for "imageconvert"
Failed to parse "imageconvert"
Invalid title/identifier for "crop_detect"
Failed to parse "crop_detect"
QQmlEngine::setContextForObject(): Object already has a QQmlContext
QQmlEngine::setContextForObject(): Object already has a QQmlContext
QObject::disconnect: Unexpected nullptr parameter
QQmlEngine::setContextForObject(): Object already has a QQmlContext
QQmlEngine::setContextForObject(): Object already has a QQmlContext
qrc:/qml/timeline.qml:1868:5: QML Connections: Implicitly defined onFoo properties in Connections are deprecated. Use this syntax instead: function onFoo(<arguments>) { ... }
QWaylandGLContext::makeCurrent: eglError: 3009, this: 0x557a2d7391e0 

QWaylandGLContext::makeCurrent: eglError: 3009, this: 0x557a2fc82b30 

QWaylandGLContext::makeCurrent: eglError: 3009, this: 0x7fd8c0007b50 

QOpenGLFunctions created with non-current context
The Wayland connection experienced a fatal error: Mauvais descripteur de fichier
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