TensorFlow ImportError: "DLL load failed" and "No module named pywrap_tensorflow_internal"

Question

I am trying to install TensorFlow (not GPU version) on Windows 7. I have installed Python 3.5.2, which I can verify:

$ python --version
Python 3.5.2

I installed TensorFlow using the following command, and it seemed to work:

$ pip3 install --upgrade tensorflow

But when I enter the Python shell to validate the installation, I get this error:

>>> import tensorflow as tf
Traceback (most recent call last):
  File "C:\Users\kimlesj1\AppData\Local\Programs\Python\Python35\lib\site-packages\tensorflow\python\pywrap_tensorflow_internal.py", line 18, in swig_import_helper
    return importlib.import_module(mname)
  File "C:\Users\kimlesj1\AppData\Local\Programs\Python\Python35\lib\importlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 986, in _gcd_import
  File "<frozen importlib._bootstrap>", line 969, in _find_and_load
  File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 666, in _load_unlocked
  File "<frozen importlib._bootstrap>", line 577, in module_from_spec
  File "<frozen importlib._bootstrap_external>", line 906, in create_module
  File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
ImportError: DLL load failed: The specified module could not be found.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\kimlesj1\AppData\Local\Programs\Python\Python35\lib\site-packages\tensorflow\python\pywrap_tensorflow.py", line 41, in <module>
    from tensorflow.python.pywrap_tensorflow_internal import *
  File "C:\Users\kimlesj1\AppData\Local\Programs\Python\Python35\lib\site-packages\tensorflow\python\pywrap_tensorflow_internal.py", line 21, in <module>
    _pywrap_tensorflow_internal = swig_import_helper()
  File "C:\Users\kimlesj1\AppData\Local\Programs\Python\Python35\lib\site-packages\tensorflow\python\pywrap_tensorflow_internal.py", line 20, in swig_import_helper
    return importlib.import_module('_pywrap_tensorflow_internal')
  File "C:\Users\kimlesj1\AppData\Local\Programs\Python\Python35\lib\importlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
ImportError: No module named '_pywrap_tensorflow_internal'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\kimlesj1\AppData\Local\Programs\Python\Python35\lib\site-packages\tensorflow\__init__.py", line 24, in <module>
    from tensorflow.python import *
  File "C:\Users\kimlesj1\AppData\Local\Programs\Python\Python35\lib\site-packages\tensorflow\python\__init__.py", line 51, in <module>
    from tensorflow.python import pywrap_tensorflow
  File "C:\Users\kimlesj1\AppData\Local\Programs\Python\Python35\lib\site-packages\tensorflow\python\pywrap_tensorflow.py", line 52, in <module>
    raise ImportError(msg)
ImportError: Traceback (most recent call last):
  File "C:\Users\kimlesj1\AppData\Local\Programs\Python\Python35\lib\site-packages\tensorflow\python\pywrap_tensorflow_internal.py", line 18, in swig_import_helper
    return importlib.import_module(mname)
  File "C:\Users\kimlesj1\AppData\Local\Programs\Python\Python35\lib\importlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 986, in _gcd_import
  File "<frozen importlib._bootstrap>", line 969, in _find_and_load
  File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 666, in _load_unlocked
  File "<frozen importlib._bootstrap>", line 577, in module_from_spec
  File "<frozen importlib._bootstrap_external>", line 906, in create_module
  File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
ImportError: DLL load failed: The specified module could not be found.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\kimlesj1\AppData\Local\Programs\Python\Python35\lib\site-packages\tensorflow\python\pywrap_tensorflow.py", line 41, in <module>
    from tensorflow.python.pywrap_tensorflow_internal import *
  File "C:\Users\kimlesj1\AppData\Local\Programs\Python\Python35\lib\site-packages\tensorflow\python\pywrap_tensorflow_internal.py", line 21, in <module>
    _pywrap_tensorflow_internal = swig_import_helper()
  File "C:\Users\kimlesj1\AppData\Local\Programs\Python\Python35\lib\site-packages\tensorflow\python\pywrap_tensorflow_internal.py", line 20, in swig_import_helper
    return importlib.import_module('_pywrap_tensorflow_internal')
  File "C:\Users\kimlesj1\AppData\Local\Programs\Python\Python35\lib\importlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
ImportError: No module named '_pywrap_tensorflow_internal'


Failed to load the native TensorFlow runtime.

See https://www.tensorflow.org/install/install_sources#common_installation_problems

for some common reasons and solutions.  Include the entire stack trace
above this error message when asking for help.

Answer 1

This is a known issue while installing tensorflow-gpu.

If you are using conda the best way to solve this problem is by doing a conda installation of tensorflow-gpu. The steps are given below. (Tested in both Windows 10 and Ubuntu 16.04)

Uninstall existing installation of tensorflow-gpu

pip uninstall tensorflow-gpu

Then install the tensorflow-gpu using conda

conda install tensorflow-gpu

This should install tensorflow-gpu in your conda environment with all the dependencies.

If you are not using anaconda distribution of python, you may try using the correct versions of cudatoolkit, CuDNN and python. A list of common errors and their corresponding github threads with solutions can be found here.

https://www.tensorflow.org/install/errors

I would recommend you to use conda install than pip install if you don't want to spent much time on figuring out what went wrong and how to fix it.

Answer 2

In my case, either cudnn v5 or v6 cannot work alone. I looked into the self check script, it seems that the proper installation of both cudnn64_5.dll and cudnn64_6.dll are checked:

cudnn5_found = False
try:
  cudnn5 = ctypes.WinDLL("cudnn64_5.dll")
  cudnn5_found = True
except OSError:
  candidate_explanation = True
  print("""
  - Could not load 'cudnn64_5.dll'. The GPU version of TensorFlow
  requires that this DLL be installed in a directory that is named in
  your %PATH% environment variable. Note that installing cuDNN is a
  separate step from installing CUDA, and it is often found in a
  different directory from the CUDA DLLs. You may install the
  necessary DLL by downloading cuDNN 5.1 from this URL:
  https://developer.nvidia.com/cudnn""")

cudnn6_found = False
try:
  cudnn = ctypes.WinDLL("cudnn64_6.dll")
  cudnn6_found = True
except OSError:
  candidate_explanation = True

if not cudnn5_found or not cudnn6_found:
  print()
  if not cudnn5_found and not cudnn6_found:
    print("- Could not find cuDNN.")
  elif not cudnn5_found:
   print("- Could not find cuDNN 5.1.")
else:
  print("- Could not find cuDNN 6.")
  print("""
  The GPU version of TensorFlow requires that the correct cuDNN DLL be 
  installed
  in a directory that is named in your %PATH% environment variable. Note 
  that
  installing cuDNN is a separate step from installing CUDA, and it is often
  found in a different directory from the CUDA DLLs. The correct version of
  cuDNN depends on your version of TensorFlow:

  * TensorFlow 1.2.1 or earlier requires cuDNN 5.1. ('cudnn64_5.dll')
  * TensorFlow 1.3 or later requires cuDNN 6. ('cudnn64_6.dll')

if either v5 or v6 is not found in Path, an OSError will occur. So I put both in my Path environment variable, and the check passed.

Answer 3

The script tensorflow_self_check.py works perfectly in my case. It points out that I miss the file cudnn64_6.dll of cuDNN v6. It is important to notice that in the official guide of TensorFlow for Window (https://www.tensorflow.org/install/install_windows), they insist that it must be cuDNN v5.1 with cuDNN64_5.dll ! They should update this guide by adding this tensorflow_self_check.py script.

EDIT: I should read carefully the release note of TensorFlow 1.3.0 https://github.com/tensorflow/tensorflow/blob/r1.3/RELEASE.md: "All our prebuilt binaries have been built with cuDNN 6. We anticipate releasing TensorFlow 1.4 with cuDNN 7."