title: TypeError: The added layer must be an instance of class Layer. Found: <keras.layers.core.Dense object at 0x11f561b00>
body: <p>I have a task where I am building a model and I am trying to use sequential but I ended up having an error. I am not sure what went wrong. This is just the start of the model but can't seem to work. To add more details the generator code is where I import the data and use it as an image generator. Deep code is code where I am building the model.</p>
  
  <p>Deep Code:</p>
  
  <pre><code>import tensorflow as tf
  from tensorflow import keras
  import numpy as np
  
  print(tf.__version__)
  from generators import ImageGenerator
  
  imagegenerator = ImageGenerator(3)
  
  model = keras.Sequential()
  model.add(Dense(32,activation='relu', input_shape=()))
  model.compile(optimizer='rmsprop',
                loss='categorical_crossentropy',
                metrics=['accuracy'])
  
  
  model.fit_generator(imagegenerator,epochs=20)
  </code></pre>
  
  <p>generator code:</p>
  
  <pre><code>from PIL import Image, ImageDraw, ImageFont, ImageFilter
  import numpy as np
  import string, random
  import keras
  
  import abc
  ABC = abc.ABCMeta('ABC', (object,), {'__slots__': ()})
  
  -----
  </code></pre>