title: Can not convert a ndarray into a Tensor or Operation error in TensorFlow model
body: <p>I am implementing a Wasserstein DCGAN in TensorFlow. The error occurs when this line is run : <code>train_image = sess.run(image_batch)</code>. The handling of this exception throws another exception</p>
  
  <pre><code>Fetch argument array([[[0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0],
          ...,
          [0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0]],
  
         [[0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0],
          ...,
          [0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0]],
  
         [[0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0],
          ...,
          [0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0]],
  
         ...,
  
         [[0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0],
          ...,
          [0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0]],
  
         [[0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0],
          ...,
          [0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0]],
  
         [[0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0],
          ...,
          [0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0],
          [0, 0, 0, ..., 0, 0, 0]]], dtype=uint8) has invalid type &lt;class 'numpy.ndarray'&gt;, must be a string or Tensor. (Can not convert a ndarray into a Tensor or Operation.)
  </code></pre>
  
  <p>I am using the MNIST dataset fetched using this command --> </p>
  
  <p><code>from keras.datasets import mnist
   (X_train, Y_train), (X_test, Y_test) = mnist.load_data()</code></p>
  
  <p>COMPLETE SOURCE CODE : <a href="https://github.com/tanmay-bhatnagar/W-DCGAN" rel="nofollow noreferrer">https://github.com/tanmay-bhatnagar/W-DCGAN</a>
  Using TensorFlow 1.4.1 and python 3.6 with latest version of all other libraries.
  Please ask for any other details that are required.</p>