Handle ImportError as MissingDependencyException

[sentry-io]

Sentry Issue: RASA-OPEN-SOURCE-91E

ImportError: DLL load failed while importing _pywrap_tensorflow_internal: A dynamic link library (DLL) initialization routine failed.
  File "site-packages\tensorflow\python\pywrap_tensorflow.py", line 64, in <module>
    from tensorflow.python._pywrap_tensorflow_internal import *

ImportError: Traceback (most recent call last):
  File "c:\users\hp pc\appdata\local\programs\python\python38\lib\site-packages\tensorflow\python\pywrap_tensorflow.py", line 64, in <module>
    from tensorflow.python._pywrap_tensorflow_internal import *
ImportError: DLL load failed while importing _pywrap_tensorflow_internal: A dynamic link library (DLL) initialization routine failed.


Failed to load the native TensorFlow runtime.

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

for some common reasons and solutions....
(13 additional frame(s) were not displayed)
...
  File "rasa\model_training.py", line 22, in <module>
    from rasa.nlu.model import Interpreter
  File "rasa\nlu\model.py", line 14, in <module>
    from rasa.nlu import components, utils
  File "rasa\nlu\components.py", line 7, in <module>
    import rasa.utils.train_utils
  File "rasa\utils\train_utils.py", line 37, in <module>
    from rasa.utils.tensorflow.callback import RasaTrainingLogger, RasaModelCheckpoint
  File "rasa\utils\tensorflow\callback.py", line 5, in <module>
    import tensorflow as tf

Definition of Done:

• wrap import in try-except block and raise MissingDependencyException from ImportError

[sentry-io]

Sentry issue: RASA-OPEN-SOURCE-8V0

[ancalita]

Having lookep up this error in Tensorflow Github community issues, I have found a few threads that could be useful in resolving this issue:

• ImportError: DLL load failed while importing _pywrap_tensorflow_internal: A dynamic link library (DLL) initialization routine failed. tensorflow/tensorflow#44110 (comment)
• ImportError: DLL load failed while importing _pywrap_tensorflow_internal: A dynamic link library (DLL) initialization routine failed. tensorflow/tensorflow#44110 (comment)
• Help! I have an issue when importing TF! tensorflow/tensorflow#36167 (comment)

[ancalita]

Handled by PR #8697