I tried to installed this n my debian machine, but I got stuck on the forst step. I cannot add the repository to my sources list. I get this error message : (freely translated from my native language) W: GPG error: http://www.debian-multimedia.org testing Release: Following signatures could not be verified because the open keys is not available: NO_PUBKEY 07DC563D1F41B907 Have tried all the repos with same result any ideas?
gpg --keyserver subkeys.pgp.net --recv 07DC563D1F41B907 gpg --export --armor 07DC563D1F41B907 | sudo apt-key add -