Hi LeRoy
Results from # apt-get update Mostly successful, threw the following errors: Err:11 http://ppa.launchpad.net/kdenlive/kdenlive-stable/ubuntu focal/main amd64 Packages 404 Not Found [IP: 91.189.95.83 80]
You need to take the kdenlive ppa out of your apt config. Adding Ubuntu repositories to your Debian is a good way to break your system.
... E: The method driver /usr/lib/apt/methods/https could not be found. ... E: Failed to fetch https://download.jitsi.org/stable/InRelease E: Failed to fetch http://ppa.launchpad.net/kdenlive/kdenlive-stable/ubuntu/dists/focal/main/bi... 404 Not Found [IP: 91.189.95.83 80] E: Some index files failed to download. They have been ignored, or old ones used instead.
Results from # apt-get install kdenlive openshot flowblade lives olive-editor pitivi Mostly successful, threw the following error: E: Unable to locate package olive-editor
Remove the ppa first and try again.
Results from # apt-get install lives-plugins 2 newly installed
This would have installed lives and lives-plugins. Nothing else