Created attachment 134636 [details] Backtrace report SUMMARY I already had several clips in the timeline, with 5 video and 5 audio slots open. I had just deleted a clip from the timeline and selected a different section from the same source video. Kdenlive crashed when I tried to drag from the clip window to the timeline. ADDITIONAL INFORMATION KDE crash reporter failed to submit the report ('Did not receive a token') so crash report and backtrace are attached here.
It looks like a QT thread issue which leads to a crash. Please try with the current Kdenlive AppImage version 20.21.1 to see if there are any packaging issues https://download.kde.org/stable/kdenlive/20.12/linux/
I thrashed the appimage version quite hard without provoking a crash. The OpenSuSE version still crashes fairly regularly (but is not reliably repeatable). Unfortunately I cannot swap to the appimage version for production work as I cannot find a way to make it recognise the audio plugins.
As this seems to be related to Qt and does not happen with the Appimage I am closing this now.