How to use Fast Protocol in c# Using OpenFast

Question

im working on Fast Protocol, so im reseving UDP package and i need to resolve.

here is some example

  <template id="65" name="Sample">
    <uInt32 name="SenderCompID" id="49"/>
    <byteVector name="PacketSeqNum"/>
    <byteVector name="SendingTime"/>
  </template>

this is the sample file.

using OpenFAST.Template;
using OpenFAST.Template.Types;
using OpenFAST.Template.Operators;
using OpenFAST;
using OpenFAST.Codec;

OpenFAST.Context _context = new OpenFAST.Context();
public void OpenFastX(byte[] bMCXPckt)
{
    try
    {
        MemoryStream ms = new MemoryStream(bMCXPckt);
        BinaryReader br = new BinaryReader(ms, Encoding.ASCII);

        MessageTemplate message = new MessageTemplate("Sample", new Field[]
        {
          new Scalar("SenderCompID",FastType.U32,Operator.Copy,ScalarValue.Undefined,false),
          new Scalar("PacketSeqNum",FastType.ByteVector,Operator.Copy,ScalarValue.Undefined,false),
          new Scalar("SendingTime",FastType.ByteVector,Operator.Copy,ScalarValue.Undefined,false),
        });
        _context.RegisterTemplate(65, message);
         
        Log.Process("Template Registered");
        var decoder = new FastDecoder(_context, new BufferedStream(ms, 65535));
        Log.Process("Decoder -: " + decoder.ReadMessage().GetInt(49).ToString());
    }
    catch (Exception ex)
    {
        Log.Error(ex.Message + Environment.NewLine + ex.StackTrace.ToString());  
    }
}

getting exception -> "An error while decoding Sample"