To clarify, there are two bugs here. One is that Software Center doesn't work without PolicyKit running (could use gksu or similar as a fallback), and the other is that Software Center doesn't show an error to the user if there is an unhandled exception.
To clarify, there are two bugs here. One is that Software Center doesn't work without PolicyKit running (could use gksu or similar as a fallback), and the other is that Software Center doesn't show an error to the user if there is an unhandled exception.