Cisco AnyConnect Client and the “Unable to process response from…” Error Message

If you get an error message saying: “Unable to process response from…” with the Cisco AnyConnect VPN client on Ubuntu, then the underlying problem is that the client is attempting to use the https_proxy environment variable to resolve the HTTP/S proxy to use.

Not sure why exactly this causes a problem but the way to workaround this problem is to unset the https_proxy variable just for the process launching the VPN client. For example I’ve added a script named: vpnui to my ~/bin with the following contents:

unset https_proxy

Then I changed the Applications|Internet|Cisco AnyConnect VPN Client menu shortcut to point to this script instead, and voila, problem solved.