tensorflow: Error while trying to serilize Image Captioning keras model '_UserObject' object is not callable'

System information

• Have I written custom code (as opposed to using a stock example script provided in TensorFlow): example from https://www.tensorflow.org/tutorials/text/image_captioning

• OS Platform and Distribution:Linux Ubuntu 18

• TensorFlow installed from (source or binary): bin

• TensorFlow version (use command below): v2.0.0-rc2-26-g64c3d38 2.0.0

• Python version: 3.6.8

Describe the current behavior

tf.saved_model.save(encoder, “./models/1/encoder”)

model get serialized with errors

Describe the expected behavior encoder can be loaded without errors

Code to reproduce the issue

• train the model from https://www.tensorflow.org/tutorials/text/image_captioning example

tf.saved_model.save(encoder, "./models/1/encoder")
encoder = tf.saved_model.load("./models/1/encoder")
encoder(img_tensor_val)

raises the error > ‘_UserObject’ object is not callable

encoder.fc(img_tensor_val) ValueError: Could not find matching function to call loaded from the SavedModel. Got: Positional arguments (1 total): * Tensor(“inputs:0”, shape=(1, 120, 64), dtype=float32) Keyword arguments: {}

Expected these arguments to match one of the following 0 option(s):

Other info / logs W1227 00:41:32.831883 139767989909312 save_impl.py:77] Skipping full serialization of Keras model <main.CNN_Encoder object at 0x7f1daf5354e0>, because its inputs are not defined.