c# Protobuf 序列化与反序列化时候报错

报错：Invalid field in source data: 0
代码：

    /// <summary>
    /// 序列化成proto
    /// </summary>
    /// <param name="msg"></param>
    /// <returns></returns>
    public static byte[] Serialize(MuffinMsg msg)
    {
        MemoryStream memStream = new MemoryStream();
        ProtoBuf.Serializer.SerializeWithLengthPrefix<IExtensible>(memStream, msg.pBObject as IExtensible,PrefixStyle.Base128);
        byte[] x = memStream.ToArray();
        memStream.Close();
        return x;
    }

             case NetMessageDef.ReqCreateAccount:
                {
                    MemoryStream ms = new MemoryStream(bytes);
                    ms.Position += 2;
                    return ProtoBuf.Serializer.DeserializeWithLengthPrefix<protos.Login.ReqCreateAccount>(ms, PrefixStyle.Base128);
                }

ms.Position += 2; 这里手动的将位置向前移动了2个，是因为之前如果不移动会解析出乱码，例如解析前的数据 W15010207 解析后就会变为\n\tW15010207 手动前移两个后 就可以解析，但是当我解析数据量较大的类或者字符串（也就几百BYTE）就会报错 Invalid field in source data: 0 求Protobuf大神帮忙求解。谢谢啦

http://blog.csdn.net/laipixiaoxi/article/details/50337117