since I don't know when Synaptic does not work. When I launch Synaptic from the dash, the icon appears for some seconds, that's all. On the other hand, Synaptic works, when I launch it from the terminal. How can I fix this?
$ synaptic-pkexec ==== AUTHENTICATING FOR com.ubuntu.pkexec.synaptic === Authentication is required to run the Synaptic Package Manager Authenticating as: Christian Hartmann,,, (christian) Password: polkit-agent-helper-1: error response to PolicyKit daemon: GDBus.Error:org.freedesktop.PolicyKit1.Error.Failed: No session for cookie ==== AUTHENTICATION FAILED === Error executing command as another user: Not authorized This incident has been reported.