It's very strange, but I've just execute apt update && apt upgrade, reboot. And now vpnc works fine! My issue solved
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1725779 Title: Gnome network manager cannot find authentication binary To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager-pptp/+bug/1725779/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
