Loading ensemble keras model gives ValueError: Invalid input_shape argument (None, 224, 224, 3): model has 0 tensor inputs

Question

My model is an ensemble of 2 different keras models, the models are connected to same input layer and have 2 output layers when combined. Both models are pretrained and I am trying to create a parallel architecture. My architecture is: `

model_input = Input(shape=(224,224,3), name="model_input")
gender_model_copy.layers.pop(0)
color_model_copy.layers.pop(0)
color_model_ens1 = color_model_copy(model_input)
gender_model_ens1 = gender_model_copy(model_input)
model_f = Model(input=[model_input], output=[color_model_ens1,gender_model_ens1])
model_f.save('path')

`

The model gets compiled and I can make predictions as well but when I save it and try to reload it I get, I get:

ValueError: Invalid input_shape argument (None, 224, 224, 3): model has 0 tensor inputs. Full trace: Github gist link .

I have a custom layer which I am adding by using custom_objects={'Scale':Scale()} argument in keras.models.load_model My keras version is 2.2.5 and tensorflow version is 1.15

EDIT : I realized that the problem was that I was making layers untrainable by layer.trainable=False , without doing that I was able to load the models without the error. I would still like to know why that happens.

Answer 1

If you rename one of your layers, it could be problem. Stop renaming.