Synaptic package manager was working in my Ubuntu 12.04 installation under Unity, but it recently stopped working for no apparent reason. It does work when I switch to KDE. Suggestions?
I had a similar problem some time ago. I solved typing in a terminal:
But you sould provide further details to understand if you have the same problem I had. If the above solution won't work, please edit your answer with verbose information, such as the output of running synaptic by terminal.