BadVersion usually means there's junk in the response, this would be caused by warnings or error messages being output into the same stream as the response body. The literal meaning of this message is that the Flash AMF parser could not understand what's been sent to it. Check for any code that may cause errors or warnings on the server side. I use Charles Proxy for watching the AMF communication - it is not a free program, but it has an evaluation version, that doesn't expire, but keeps annoying you with "buy me" sort of messages. Actually, I think it's worth the money, but, that's up to you.
Best. Oleg
