basic retrieval tutorial savedmodel `Op type not registered 'Scann>TensorsToScann'` error

I ran the basic_retrieval.ipynb tutorial and deployed the savedmodel.
When sent query to tf serving, the following error occurs:
tensorflow.python.framework.errors_impl.NotFoundError: Op type not registered 'Scann>TensorsToScann' in binary running on managed-notebook-cb8e4-0. Make sure the Op and Kernel are registered in the binary running in this process. Note that if you are loading a saved graph which used ops from tf.contrib, accessing (e.g.) tf.contrib.resampler should be done before importing the graph, as contrib ops are lazily registered when the module is first accessed.
The same error happened when using saved_model_cli show command to inspect the saved model.