Comment 1 for bug 68469

kdesu doesn't start because you are logged in as ubuntu, a password-less account with sudo privileges. I suspect that `kdesu wlassistant` is still what's being run, but since your user doesn't have a password the kdesu password prompt never appears.

If I have misinterpreted the bug, please provide more information and we'll see what we can do. Thanks for your bug report.