title: What is error "ImportError: numpy.core.multiarray failed to import"?
body: <p>I was working on a project that needed numpy. I used pip install numpy and got the message it is already installed. After completing that code and when I was running a different code I get the following error which did not happen before. I am using Python 3.6. Same versions before and after the issue.</p>
  
  <p>Client code : </p>
  
  <pre><code>import requests
  #import json
  from keras.preprocessing.image import img_to_array, array_to_img, load_img
  from keras.preprocessing import image
  
  flowers = 'c:/flower_photos/daisy/107592979_aaa9cdfe78_m.jpg'
  #for x in flowers:
  image1 = img_to_array(image.load_img(flowers, target_size=(128,128))) / 255
  payload = {
        "instances": [{"image":image1.tolist()},
  ]
  }
  print("sending request...")
  r = requests.post('http://localhost:8501/v1/models/flowers/versions/1:predict', json=payload)
  #r = requests.get('http://localhost:8051/v1/models/modelflowers/versions/1/metadata')
  print(r.content)
  </code></pre>
  
  <p>I get the following error :</p>
  
  <pre><code>C:\flowers_old&gt;client.py
  Using TensorFlow backend.
  ModuleNotFoundError: No module named 'numpy.core._multiarray_umath'
  ImportError: numpy.core.multiarray failed to import
  
  The above exception was the direct cause of the following exception:
  
  Traceback (most recent call last):
    File "&lt;frozen importlib._bootstrap&gt;", line 980, in _find_and_load
  SystemError: &lt;class '_frozen_importlib._ModuleLockManager'&gt; returned a result with an error set
  ImportError: numpy.core._multiarray_umath failed to import
  ImportError: numpy.core.umath failed to import
  2019-02-10 19:15:06.355011: F tensorflow/python/lib/core/bfloat16.cc:675] Check failed: PyBfloat16_Type.tp_base != nullptr
  </code></pre>
  
  <p>I uninstalled both TF and numpy and put them back. Still the same error.
  Any help ?</p>
  
  <p>Thanks,
  Pubudu</p>