It is a benign error that means your client couldn't connect to our server which tells you what the latest version is.An error occurred when trying to retrieve version.xml
The version.xml request is sent via HTTP on port 80. The URL is http://sourcegear.com/vault/version.xml. If you can get your browser to display the version, that should help in your troubleshooting.
This error has no impact on your Vault operations -- it's informational only, to remind users they may not be on the latest version.
You can turn it off in the Client under Tools-Options-General->Check for latest Vault Version at startup.