title: NotImplementedError when creating keras model with LSTM layer in Visual Studio 2017
body: <p>My code is:</p>
  <pre><code>import tensorflow as tf
  keras_model = tf.keras.Sequential([
      tf.keras.layers.Embedding(1000, 16),
      tf.keras.layers.LSTM(32),
  ])
  </code></pre>
  <p>I have an error:</p>
  <blockquote>
  <p>NotImplementedError: Cannot convert a symbolic Tensor
  (lstm/strided_slice:0) to a numpy array. This error may indicate that
  you're trying to pass a Tensor to a NumPy call, which is not supported</p>
  </blockquote>
  <p>Call stack:</p>
  <pre><code>Tensor.__array__ in ops line 848    Python  
  _wrapreduction in fromnumeric line 90   Python  
  prod in fromnumeric line 2962   Python  
  prod in C:\Users\FA\Google Drive\Colab Notebooks\PoetryTransformer\Accentizer\&lt;__array_function__ internals&gt; line 6 Python  
  _constant_if_small in array_ops line 2732   Python  
  zeros in array_ops line 2794    Python  
  wrapped in _tag_zeros_tensor in array_ops line 2747 Python  
  wrapper in add_dispatch_support in dispatch line 201    Python  
  create_zeros in _generate_zero_filled_state in recurrent line 2981  Python  
  &lt;listcomp&gt; in nest line 635 Python  
  map_structure in nest line 635  Python  
  _generate_zero_filled_state in recurrent line 2984  Python  
  _generate_zero_filled_state_for_cell in recurrent line 2968 Python  
  LSTMCell.get_initial_state in recurrent line 2524   Python  
  RNN.get_initial_state in recurrent line 646 Python  
  RNN._process_inputs in recurrent line 862   Python  
  LSTM.call in recurrent_v2 line 1108 Python  
  Layer._functional_construction_call in base_layer line 1117 Python  
  Layer.__call__ in base_layer line 926   Python  
  RNN.__call__ in recurrent line 663  Python  
  Sequential.add in sequential line 221   Python  
  _method_wrapper in no_automatic_dependency_tracking in base line 457    Python  
  Sequential.__init__ in sequential line 142  Python  
  _method_wrapper in no_automatic_dependency_tracking in base line 457    Python  
  ragged module line 5    Python  
  </code></pre>
  <p>I can not add LSTM layer neither with Sequentional API nor with Functional API.
  Custom model works well.
  What could be a reason of that ?</p>
  <p>Tensorflow version is 2.3.0.
  Python version 3.6.</p>
  <p>The error relates to Visual Studio (no error when I am running w/o VS).</p>