I'm trying to install flash via the software center and I get this error :
"Software can't be installed or removed because the authentication service is not
available. (org.freedesktop.PolicyKit.Error.Failed: ('system-bus-name', {'name':
':1.51'}): org.debian.apt.install-or-remove-packages"
I checked the startup applications and found that the policy kit authentication agent was checked.
I then tried to use /usr/lib/policykit-1-gnome/polkit-gnome-authentication-agent-1
and received this error message:
(polkit-gnome-authentication-agent-1:25835): polkit-gnome-1-WARNING **:
Unable to determine the session we are in: No session for pid 25835
The error appears to be avoided by running software center in root mode by using
gksu software-center
or by installing it via command mode e.g. sudo apt-get install flashplugin-installer
Best Answer
Since PolicyKit seems to be installed and apt-get is working, try the following command