http://www.coderanch.com/t/625696/Web-Services/java/Invalid-HTTP-server-response-Length

As William asked, please share how you are setting content length in SOAP header.

I searched online for error and found that there can be one more reason for this failure.

Reason - The remote WSEndpoint did not like the HTTP Chunking feature activated. Try disabling this feature for WS client.

netty

HttpPostRequestEncoder bodyRequestEncoder = new HttpPostRequestEncoder(factory, request, false);