Lubuntu 14.10 won't update or shutdown

Question

I started up my computer and used the terminal to check some network settings, but when I tried to turn it off again, a message shows up at the bottom of the shut down menu:

"GDBus.Error:org.freedesktop.DBus.Error.AccessDenied: Operation not permitted"

I figured it had something to do with needing to update, but when I tried to do that, it gives me the message:

You are not allowed to perform this action

You don't have the required privileges to perform this action.

Why would it tell me that when I'm the ONLY user!?

I'm currently using Lubuntu 14.10, please help me!

Answer 1

I have a similar problem on Lubuntu 14.04, with the added nuisance of a bunch of error boxes popping up on booting. After a bit of digging, I have concluded that the following might be relevant:

1. /usr/lib/policykit-1-gnome/polkit-gnome-authentication-agent-1 is not running (not listed when I run ps aux | grep pol). Attempting to start it throws:

   Cannot register authentication agent: GDBus.Error:org.freedesktop.PolicyKit1.Error.NotSupported: Operation not supported
   

2. pkexec has segfaulted at some point during the boot, and is broken. Running pkexec echo 'test' results in a segfault.

3. This line in my auth.log:

   gnome-keyring-daemon[1255]: couldn't set environment variable in session: The name org.gnome.SessionManager was not provided by any .service files
   

4. I have tried the solutions listed here, without success.

5. I have tried reinstalling policykit-1-gnome and gnome-keyring, without success.

Lastly, the only workaround I've found is running sudo shutdown now from a terminal.