Web service connection fails with the error: “The underlying connection was closed: An unexpected error occurred on a send”

Symptom

A task using the Web Service Connector Tool to make a secure call is failing at runtime with the following error; this also occurs if the web service connection is tested via the connector tool global configuration.

iwwshr.Exceptions.WebServiceCallFailedException: The underlying connection was closed: An unexpected error occurred on a send.

Cause

The connection is failing to establish a secure HTTPS channel.

A Windows update has occurred on the machine which has patched against an SSL3 layer vulnerability. Most likely, the components replaced have not been fully embedded and are preventing the secure connection from operating as normal until a reboot has been completed.

Solution

Reboot the machine and test the web service connection again.