Unable to convert to frozen graph or checkpoint

[venkat-kittu]

I am trying to convert the densenet161 model to frozen graph(pb) or checkpoint, but after loading the model and while saving the checkpoint file I am getting the below error.
Thanks in advance

tensorflow.python.framework.errors_impl.FailedPreconditionError: Attempting to use uninitialized value batch_normalization_1/beta
[[node save/SaveV2 (defined at /usr/local/lib/python3.6/dist-packages/tensorflow_core/python/framework/ops.py:1748) ]]

Below is the code for your reference

import densenet
import tensorflow as tf
model = densenet.DenseNetImageNet161(input_shape=(224,224,3))
saver = tf.train.Saver()
sess = tf.keras.backend.get_session()
save_path = saver.save(sess, "./checkpoint/model")

getting issue in the last line of code.