This looks like a Windows registry problem based on your error. First i would restart you machine, then open your device manager and look for any warning icons on network adapters, try disabling/re-enabling them. This does not look like a sandbox issue, more an issue on your local machine.
When does this message appear, you have entered the sandbox endpoint/gateway in Anyconnect (or are you using another VPN client?), then your username/password (all of these were sent on the email), then this error appears?
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