Ubuntu 1404 b2 - "you don't have priviledges to install updates" and any system modification is refused

[Ian Scott]

This is a serious bug as it stops all updates even corrections! It also stops logging out as this needs priveldges. The only solution is the power switch! Also, even as a VM, rather than as a native OS, this can mean host shutdown.

[Ian Scott (arb-xfm)]

This bug showed today on 2 VMs on Win 8.1 and one native OS on another notebook - after I used "software updater". Will this bug allow repair as it prevents updates?

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[pico (pico-cocco)]

I confirm the problems after a partial upgrate

Ubuntu Release: 14.04
Problems:
 - Update manager do not work : "You are not allowed to perform this action"
- Audio do not work
- Shutdown/reboot not possible from GUI
- VPN and Network Config edit NOT Possible
- USB or externa disk not mounted
- Even other root actions are not allowed from GUI (add user, and so on..)

Triing to install new SW from SW center I have:
Software can't be installed or removed because the authentication service is not available. (org.freedesktop.PolicyKit.Error.Failed: ('system-bus-name', {'name': ':1.199'}): org.debian.apt.install-or-remove-packages

I think the problem is related to the PolicyKit, but I'm not sure...
Regards
P.