I had the same error. So I installed gnome-software-plugin-flatpak and flatpak :
$ sudo add-apt-repository ppa:alexlarsson/flatpak && sudo apt update $ sudo apt install flatpak But still had the same error. I rebooted and had the install button (with the other error Martin noticed too on #3). Unfortunately that doesn't worked too. I had an other error (the third...) that I attached. Note the installation work from command line. ** Attachment added: "Capture du 2018-01-31 13-37-12.png" https://bugs.launchpad.net/ubuntu/+source/gnome-software/+bug/1716409/+attachment/5046342/+files/Capture%20du%202018-01-31%2013-37-12.png -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-software in Ubuntu. https://bugs.launchpad.net/bugs/1716409 Title: Unable to install flatpak on Ubuntu artful To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-software/+bug/1716409/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
