HTTP “broken pipe” Error on non-Windows Systems (Linux, iOS, MacOSX, etc.)

If you see the error lines “The connection already exists, as far as we know..” followed by “socketError: Broken pipe”  in any LastErrorText for a method that sends an HTTP request, it means the following:   The server replied to the previous request without a “Connection: close” header, thus allowing the client to keep the connection open for the next request.  […]