I think this is a known issue in other versions. From /var/log/syslog:
Nov 3 15:13:55 somemachine NetworkManager[1048]: <info> Starting VPN service 'vpnc'...
Nov 3 15:13:55 somemachine NetworkManager[1048]: <info> VPN service 'vpnc' started (org.freedesktop.NetworkManager.vpnc), PID 11049
Nov 3 15:13:55 somemachine NetworkManager[1048]: <info> VPN service 'vpnc' appeared; activating connections
Nov 3 15:14:37 somemachine NetworkManager[1048]: <info> VPN plugin state changed: starting (3)
Nov 3 15:14:37 somemachine NetworkManager[1048]: <info> VPN connection 'Blue Nile' (Connect) reply received.
Nov 3 15:14:37 somemachine NetworkManager[1048]: SCPlugin-Ifupdown: devices added (path: /sys/devices/virtual/net/tun0, iface: tun0)
Nov 3 15:14:37 somemachine NetworkManager[1048]: SCPlugin-Ifupdown: device added (path: /sys/devices/virtual/net/tun0, iface: tun0): no ifupdown configuration found.
Nov 3 15:14:37 somemachine NetworkManager[1048]: <warn> /sys/devices/virtual/net/tun0: couldn't determine device driver; ignoring...
Nov 3 15:14:40 somemachine NetworkManager[1048]: SCPlugin-Ifupdown: devices removed (path: /sys/devices/virtual/net/tun0, iface: tun0)
Nov 3 15:14:40 somemachine NetworkManager[1048]: <warn> VPN plugin failed: 1
Nov 3 15:14:40 somemachine NetworkManager[1048]: <info> VPN plugin state changed: stopped (6)
Nov 3 15:14:40 somemachine NetworkManager[1048]: <info> VPN plugin state change reason: 0
Nov 3 15:14:40 somemachine NetworkManager[1048]: <info> Policy set 'Auto Ethernet' (eth2) as default for IPv4 routing and DNS.
Nov 3 15:14:40 somemachine NetworkManager[1048]: <info> Policy set 'Auto Ethernet' (eth2) as default for IPv6 routing and DNS.
Nov 3 15:14:40 somemachine NetworkManager[1048]: <warn> error disconnecting VPN: Could not process the request because no VPN connection was active.
Nov 3 15:14:44 somemachine NetworkManager[1048]: <info> VPN service 'vpnc' disappeared
Traffic online suggested it had something to do with a recent update, and so the proposed fix was:
sudo apt-get install libgcrypt11=1.5.0-3ubuntu3
…but same problem. The error message is different if I use the wrong credentials. Note that this is happening on both of my machines so I suspect it is related to an update.
Last successful connection was 20 days ago from today, 5 Nov 2014.
Best Answer
OK I think I understand this one now. I created a Windows VM, installed the Cisco client and configured it with my credentials. I got in to the VPN with no problems but I noticed some interesting behavior that perhaps is not handled by many Linux clients. I had just changed my Windows password on the target Windows desktop box inside the VPN, which is what I think triggered this. When I logged in using Windows 7 and the official Cisco client it prompted me not once but TWICE for an RSA passcode. The second time I was specifically prompted for the NEXT passcode. Short term work-around then is to log in once from a Windows box at the remote side each time you change your Windows password. I wonder how many headaches this has caused?