Problem with tutorial

[tombinic]

I'm trying to replicate the tutorial

`model = tf.keras.applications.vgg16.VGG16(weights="imagenet", include_top=True)

img = tf.keras.preprocessing.image.load_img(IMAGE_PATH, target_size=(224, 224))
img = tf.keras.preprocessing.image.img_to_array(img)
data = ([img], None)

explainer = GradCAM()
grid = explainer.explain(data, model, class_index=281) # 281 is the tabby cat index in ImageNet

explainer.save(grid, ".", "grad_cam.png")`

it gives me an error

"AttributeError: 'Dense' object has no attribute 'output_shape'"
How can I fix it? Thank you