title: Tensorflow Serving: Expects arg[0] to be float but string is provided
body: <p>Tensorflow Serving returns the error message in the title and I don't understand why. I call it via the regress API as it is shown in the below snippet:<br>
  </p>
  
  <pre><code>using RestSharp;
  using Newtonsoft.Json;
  
  var client_myclient = new RestClient("http://192.168.100.1:8501/v1/models/mymodel:regress");
  // request preparation
  json_prep.examples.Add( blah blah blah);
  string json_prep_converted = JsonConvert.SerializeObject(json_prep, Formatting.Indented);
  var req_ = new RestRequest(Method.POST);
  req_.AddJsonBody(json_prep_converted);
  // response
  var res_mymodel = client_myclient.Execute(req_candle);
  </code></pre>
  
  <p>My error message contains the following request confirming what I sent; it is only a single example exactly as shown below except that the ... omits several entries:
  </p>
  
  <pre><code>{
    "examples": [
      {
        "a": [
          1.937336,
          ...
          -5.107522
        ],
        "b": [
          -0.704486,
          ...
          -6.868737
        ],
        "c": [
          2.817943,
          ...
          -4.226915
        ],
        "d": [
          -3.346308,
          -...
          -7.749344
        ],
        "e": [
          1.0625,
          -0.1875,
          ...
          -0.8125
        ],
        "f": [
          0.943968,
          -1.17052,
          ...
          0.641898
        ],
        "g": [
          0.22639801,
          ...
          0.19194462
        ],
        "h": [
          -1.449828,
          ...
          0.34936
        ],
        "i": [
          -50.61624,
          ...
          -17.362056
        ],
        "j": [
          0.148651,
          ...
          -0.228189
        ],
        "k": [
          0.16410813748132047,
          ...
          0.39454449551653981
        ],
        "l": [
          0.704047,
          ...
          -1.462873
        ],
        "m": [
          4.55,
          ...
          2.54
        ]
      }
    ]
  }
  </code></pre>
  
  <p>The JSON message was double checked and it doesn't contain strings where I replaced the list body with ... (And it must not by definition)<br>
  I trying to follow the <a href="https://www.tensorflow.org/serving/api_rest#request_format" rel="nofollow noreferrer">official manual on this</a>.  </p>
  
  <p>For more details, the error in raw format is:</p>
  
  <pre><code>"{ \"error\": \"Expects arg[0] to be float but string is provided\" }"
  </code></pre>
  
  <p>How do I solve this error?</p>