title: Layer was called with an input that isn't a symbolic tensor
body: <p>I followed the code that I found on <a href="https://haptik.ai/tech/offline-on-device-ml-text-classification/" rel="nofollow noreferrer">this page</a>.</p>
  
  <p>When I copy-paste the code, I get an error:</p>
  
  <pre><code>ValueError: Layer batch_normalization_1 was called with an input that isn't a symbolic tensor.
  </code></pre>
  
  <p><a href="https://github.com/shantanuo/stack_question/blob/master/haptik_chatbot.ipynb" rel="nofollow noreferrer">https://github.com/shantanuo/stack_question/blob/master/haptik_chatbot.ipynb</a></p>
  
  <p>What is the reason that I get an error unlike the blog writer?</p>