The backtrace lacks debug symbols, so it's really hard to say where exactly kwin crashes. Can you install debug packages for kwin please and re-submit the backtrace?

*** Bug 418260 has been marked as a duplicate of this bug. ***

Hello Vlad,

thanks for your answer. I'm running on Fedora right now.

Hopes this would be sufficient :
sudo dnf debuginfo-install  kwin-common kwin kwin-wayland kf5-kwindowsystem kwin-libs

if it's then on next occurrence i will update this ticket with appropriate backtrace.

Regards,
Gregory.

Speaking of :

-- Backtrace:
Application: KWin (kwin_x11), signal: Segmentation fault

[KCrash Handler]
#4  0x0000000000000000 in  ()
#5  0x00007f28c013f564 in KWin::SceneOpenGL::createScene(QObject*) (parent=<optimized out>) at /usr/src/debug/kwin-5.20.5-1.fc33.x86_64/plugins/scenes/opengl/scene_opengl.cpp:454
#6  0x00007f28c014e41d in KWin::OpenGLFactory::create(QObject*) const (this=<optimized out>, parent=0x7f28bc003f70) at /usr/src/debug/kwin-5.20.5-1.fc33.x86_64/plugins/scenes/opengl/scene_opengl.cpp:2757
#7  0x00007f28d7bfa9e3 in KWin::Compositor::setupStart() (this=0x7f28bc003f70) at /usr/src/debug/kwin-5.20.5-1.fc33.x86_64/composite.cpp:246
#8  0x00007f28d7bfb235 in KWin::Compositor::setupStart() (this=this@entry=0x7f28bc003f70) at /usr/src/debug/kwin-5.20.5-1.fc33.x86_64/composite.cpp:296
#9  0x00007f28d7bfe03e in KWin::X11Compositor::start() (this=0x7f28bc003f70) at /usr/src/debug/kwin-5.20.5-1.fc33.x86_64/composite.cpp:961
#10 0x00007f28d7bfbe57 in KWin::Compositor::reinitialize() (this=0x7f28bc003f70) at /usr/src/debug/kwin-5.20.5-1.fc33.x86_64/composite.cpp:525
#11 0x00007f28d68ca386 in void doActivate<false>(QObject*, int, void**) () at /lib64/libQt5Core.so.5
#12 0x00007f28d68c2d1e in QObject::event(QEvent*) () at /lib64/libQt5Core.so.5
#13 0x00007f28d732fec3 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /lib64/libQt5Widgets.so.5
#14 0x00007f28d689abd8 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /lib64/libQt5Core.so.5
#15 0x00007f28d689d8c7 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /lib64/libQt5Core.so.5
#16 0x00007f28d68e4afe in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#17 0x00007f28c3110852 in QXcbUnixEventDispatcher::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5XcbQpa.so.5
#18 0x00007f28d689957b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#19 0x00007f28d68a11b4 in QCoreApplication::exec() () at /lib64/libQt5Core.so.5
#20 0x00005645b0f72aff in main ()
[Inferior 1 (process 17399) detached]

is it sufficient ?

Regards,
Gregory.

Changing status.

Yeah, it's good enough. According to the backtrace, kwin crashes at https://invent.kde.org/plasma/kwin/-/blob/v5.20.5/plugins/scenes/opengl/scene_opengl.cpp#L454 Odd...

Two recent  update on my desktop : 

- update of Nvidia driver to 460.32.03 (from 450.XX.XX)
- update of Frameworks to 5.78.0 from 5.75.X

That could be something ?

Regards,
Gregory.

janv. 13 14:05:44 kwin_x11[17399]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 63522, resource id: 15228254, major code: 3 (GetWindowAttributes), minor code: 0
janv. 13 14:05:44 kwin_x11[17399]: qt.qpa.xcb: QXcbConnection: XCB error: 9 (BadDrawable), sequence: 63523, resource id: 15228254, major code: 14 (GetGeometry), minor code: 0
janv. 13 14:09:15 kwin_x11[17399]: kwin_scene_opengl: OpenGL 2 compositing setup failed
janv. 13 14:09:15 kwin_x11[17399]: kwin_scene_opengl: OpenGL driver recommends XRender based compositing. Falling back to XRender.
janv. 13 14:09:15 kwin_x11[17399]: kwin_scene_opengl: To overwrite the detection use the environment variable KWIN_COMPOSE
janv. 13 14:09:15 kwin_x11[17399]: kwin_scene_opengl: For more information see https://community.kde.org/KWin/Environment_Variables#KWIN_COMPOSE
janv. 13 14:09:17 kwin_x11[60172]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 2589, resource id: 148897828, major code: 3 (GetWindowAttributes), minor code: 0
janv. 13 14:09:17 kwin_x11[60172]: qt.qpa.xcb: QXcbConnection: XCB error: 9 (BadDrawable), sequence: 2590, resource id: 148897828, major code: 14 (GetGeometry), minor code: 0
janv. 13 14:09:17 kwin_x11[60172]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 2645, resource id: 148897847, major code: 3 (GetWindowAttributes), minor code: 0
janv. 13 14:09:17 kwin_x11[60172]: qt.qpa.xcb: QXcbConnection: XCB error: 9 (BadDrawable), sequence: 2646, resource id: 148897847, major code: 14 (GetGeometry), minor code: 0
janv. 13 14:09:17 kwin_x11[60172]: kwin_core: Compositing is not possible
janv. 13 14:19:29 kwin_x11[60172]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 23716, resource id: 14680071, major code: 15 (QueryTree), minor code: 0

Well, that sounds like a regression introduced by the recent update of the nvidia driver. On the other hand, kwin should not crash when it falls back to the xrender backend. Not sure why it crashes at delete backend;

Created attachment 135411 [details]
New crash information added by DrKonqi

kwin_x11 (5.20.5) using Qt 5.15.2

- What I was doing when the application crashed:

Moved taskbar icon. This also happens when minimize/restore windows.

-- Backtrace (Reduced):
#5  0x00007fe6941a8fdb in KWin::SceneOpenGL::createScene(QObject*) () from /usr/lib64/qt5/plugins/org.kde.kwin.scenes/KWinSceneOpenGL.so
#6  0x00007fe6941a98b9 in KWin::OpenGLFactory::create(QObject*) const () from /usr/lib64/qt5/plugins/org.kde.kwin.scenes/KWinSceneOpenGL.so
#8  0x00007fe69d59a6e3 in KWin::X11Compositor::start() () from /usr/lib64/libkwin.so.5
#9  0x00007fe69d5985b4 in KWin::Compositor::reinitialize() () from /usr/lib64/libkwin.so.5
#10 0x00007fe69c3ba981 in void doActivate<false>(QObject*, int, void**) () from /usr/lib64/libQt5Core.so.5

*** This bug has been marked as a duplicate of bug 432570 ***