Probably it's because of flatpak's sandbox: if I install Kdenlive via flatpak and I add an animation clip, it asks where glaxnimate is, and whatever I write (snap, apt or fltpak executable of glaxnimate) nothing works. Running Kdenlive from terminal, it says there are missing libraries, but they are actually installed.

Anyone has been able to make Kdenlive see glaxnimate under flatpak environment?

(I'm using Kdenlive 12.12 under Ubuntu 22.04 - I use flatpak version because appimage doesn't see hardware acceleration, ppa wants to install all kde framework which is not good on Gnome 3, and snap is not really up-to-date and doesn't see glaxnimate too)

This is probably not possible due to the sandbox design of Flatpak. I opened an issue about: https://invent.kde.org/multimedia/kdenl ... ssues/1618.

I am using Linux Mint 21.1 Cinamon with Kdenlive 22.12.0 installed and Kdenlive environment config I can see Glaximate (0.5.1) under the app tab, but it has an "!" infront of the file name and does not work although I can run glaxnimate from the command line. I tried to install flatpack glaximate but could not get it working either.
Any other tests I can do?

Ubuntu 22.04: standalone Glaxnimate works good in any way you install it (apt, snap or flatpak). The point is it doesn't work inside the flatpak version of Kdenlive.