.netSDk 上传文件失败

var client = new OssClient(_endpoint, _accessKeyId, _accessKeySecret);
            try
            {              
                var meta = new ObjectMetadata();
                meta.ContentType = "image/jpeg";
                meta.ContentLength = picture.ContentLength;
                var result = client.PutObject(_bucketName, "/Image", picture.InputStream, meta);//上传图片
                Console.WriteLine("ETag:{0}", result.ETag);
            }
            catch (Exception ex)
            {
                Console.WriteLine("Put object failed, {0}", ex.Message);
            }


报错： 无效的对象键。 它的长度必须在1到1023之间。\ r \ n参数名：key
求解决