tensorflow: Keras Model Errors on Loading - 'list' object has no attribute 'items'

System information

• Have I written custom code (as opposed to using a stock example script provided in TensorFlow): No
• OS Platform and Distribution (e.g., Linux Ubuntu 16.04): Windows 10
• TensorFlow installed from (source or binary): pip
• TensorFlow version (use command below): 2.1.0
• Python version: 3.5.2
• CUDA/cuDNN version: CUDA 10.1 cuDNN 7.6
• GPU model and memory: Quadro M2000M 4.00GiB

Describe the current behavior

When trying to load one of my sequential models using tf.keras.models.load_model an error is thrown at the following location:

tensorflow_core\python\keras\utils\generic_utils.py", line 254, in class_and_config_for_serialized_keras_object
for key, item in cls_config.items():

This code expects cls_config to be a dictionary, while for this model it is a list of dictionaries. I can successfully load and run this model using TensorFlow versions 2.0.0, 1.14.0 and 1.4.0 (the version is was trained with)

This section of code was introduced when adding support for passive serialization in Keras

Describe the expected behavior

Can successfully load a model from a hdf5 file when its config is in the list format

Code to reproduce the issue

Execute the class_and_config_for_serialized_keras_object function with a config of the following form:

{
    "config": [
        {
            "config": 
            {
                ...
            },
            "class_name": "Conv2D"
        },
        ...
    ],
    "class_name": "Sequential"
}

Which is different from the form when I create a new model using TF v2.1.0 or 2.0.0 (I haven’t verified the form of the config with the other versions):

{
    "config": {
        "name": "sequential",
        "layers": [
            {
                "config": 
                {
                    ...
                },
                "class_name": "Conv2D"
            },
            ...
        ]
    },
    "class_name": "Sequential"
}

Other info / logs

When loaded with tf.keras in v2.0.0 the layers, model config, inputs, outputs, summary etc. are all parsed correctly, as well as being able to run data through the model.