Getting Unsupported AMF version error while using

I am trying to send AMF message using AMF Connection API but getting following error as shown below.

ClientStatusException 
message: Unsupported AMF version

I am using blazeds-core-4.0.1.21287.jar for this purpose.

Following is my code.

String url = "https://10.222.73.251:9443/vsphere-client/#";
        try {
            amfConnection.connect(url);
            System.out.println(amfConnection.getUrl());
        } catch (ClientStatusException cse) {
            System.out.println("Error connecting url: " + cse);
            return;
        }

        try {

            amfConnection.addHttpRequestHeader("Cookie",
                    "6250CED9FBC7D5894B79973DEC1503A6");
            amfConnection.addHttpRequestHeader("Content-type",
                    "application/x-amf");
            amfConnection.setAmfTrace(new AmfTrace());
            //amfConnection.setObjectEncoding(3);
            System.out.println(amfConnection.getObjectEncoding());

            CommandMessage cmsg = new CommandMessage();
            cmsg.setOperation(CommandMessage.CLIENT_PING_OPERATION);
            cmsg.setMessageId(UUIDUtils.createUUID());
            cmsg.setHeader(Message.FLEX_CLIENT_ID_HEADER, "706E5399-D81A-11C8-11F7-BE5F1940632E");
            cmsg.setHeader(Message.ENDPOINT_HEADER, "amf");
            AcknowledgeMessage ack = (AcknowledgeMessage)amfConnection.call(null, cmsg);

Any help is appreciated. :)

I had the same problem. The cause was that the server expected a "self-contained AMF packet".

See https://en.wikipedia.org/wiki/Action_Message_Format#AMF_self-contained_packet

This basically means that you need to add the following bytes in front of the "normal" AMF message:

  byte[] header = 
  { 0x00, 0x03,       // version 
    0x00, 0x00,       // nr of "header-type-structures" to follow (none) 
    0x00, 0x01,       // nr of "message-type-structures" to follow (one)
    0x00, 0x04,       // target-uri-length
    0x6e, 0x75, 0x6c, 0x6c, // target uri "null" 
    0x00, 0x04,       // response uri length 
    0x6e, 0x75, 0x6c, 0x6c, // response uri "null" 

    ??, ??, ??, ??    // the length of the "normal" message, 32 bits
  };