Neon User Edition 5.13.4 Nvidia 390.77 Steps to Reproduce: 1. Install Kdenlive from discover using the flathub source. 2. Launch the program. Launching the Kdenlive flatpak on terminal will output: libGL error: No matching fbConfigs or visuals found libGL error: failed to load driver: swrast Could not initialize GLX The program will not load. On Open source drivers it works with out problems. To make the flatpak open "flatpak update" needs to be run on a terminal so it will download and install the packaged drivers on flathub. After that the program will launch. Just reporting after trying another flatpaked KDE software that rely on Opengl and wont launch. No further testing was made than opening and closing the program.
Unfortunately, Movit is not stable. See here: Bug 380019 Disable it for the time being. *** This bug has been marked as a duplicate of bug 380019 ***