On Mon, Jul 15, 2013 at 11:11:09AM +0200, Vladimír Čunát wrote: > Interesting, for me flash worked fine with FF 22 from the beginning > (lots of youtube and others as well). Same here. With FF 21/22, the only new thing was the removal of the version in the attribute names. I only did: nix-env -iA nixos.pkgs.firefoxWrapper Regards, Lluís.