title: Cannot load tflite model, Did not get operators or tensors in subgraph 1
body: <p>I have converted a tf model to tflite, and applied quantization in the process, but I cannot load it. The error was raised when I try to do <code>interpreter = tf.lite.Interpreter(tflite_model_path)</code>, the error message was:</p>
  <pre><code>ValueError: Did not get operators or tensors in subgraph 1.
  </code></pre>
  <p>Also during quantization, I got lots of these INFO messages for every dense layer in my model:</p>
  <pre><code>2021-09-06 04:38:40.879693: I tensorflow/lite/tools/optimize/quantize_weights.cc:217] Skipping quantization of tensor bert_token_clssfification/classifier/Tensordot/Shape that is not type float.
  </code></pre>
  <p>These messages confuse me greatly, because I'm sure those weights are of type float32. Any ideas what I'm doing wrong? Thanks!</p>