I am trying to upload a word2vec file in Google Colaboratory from local system and use it further in the in code.

This is the code that I used.

from google.colab import files
uploaded = files.upload()

Everytime I execute it, it is showing the following error.

Upload widget is only available when the cell has been executed in the current browser session. Please rerun this cell to enable

 MessageError  Traceback (most recent call last)
<ipython-input-1-292f82be1b7a> in <module>()  

      1 from google.colab import files
      2 
----> 3 uploaded = files.upload()`
      4 
      5 for fn in uploaded.keys():

/usr/local/lib/python3.6/dist-packages/google/colab/files.py in upload() 

     59   result = output.eval_js(
     60       'google.colab._files._uploadFiles("{input_id}", "{output_id}")'.format(
---> 61           input_id=input_id, output_id=output_id))
     62   files = collections.defaultdict(six.binary_type)
     63 

/usr/local/lib/python3.6/dist-packages/google/colab/output/_js.py in 
eval_js(script, ignore_result)

     37   if ignore_result:
     38     return
---> 39   return _message.read_reply_from_input(request_id)
     40 
     41 

/usr/local/lib/python3.6/dist-packages/google/colab/_message.py in 
read_reply_from_input(message_id, timeout_sec)

     84         reply.get('colab_msg_id') == message_id):
     85       if 'error' in reply:
---> 86         raise MessageError(reply['error'])
     87       return reply.get('data', None)
     88 

MessageError: TypeError: google.colab._files is undefined

Why is this happening? What should I do?