Hi. Just tried to fire up the appimage and it failed... due to libjack not being there. So it seems this library should be included in the appimage. Thanks.
Which AppImage do you use?
Please try with the actual Kdenlive AppImage version 18.08.3 Run the Appimage from the terminal (press CTRL + ALT + T). Move to the AppImage folder and run the .AppImage: ./Kdenlive*.AppImage