It looks like it tried to connect to a service to send another shutdown command but the service is no longer available - because the server has shut down after the first shutdown command. I've seem to recall that problem with the 3.0.x systems - perhaps an incorrect parameter passed to the shutdown script? I can't remember the exact reason. Most people probably got around this by using a process kill rather than using the shutdown client - I think the go.sh script works along those lines.
In 3.2.x, this problem does not occur for shutdown.sh running on the same platform.