How to fix VK API Python error?

Question

Python

When using the script , it gives the following errors:

Traceback (most recent call last):
  File "vk.py", line 258, in <module>
    friends = GetFriends(user_id)
  File "vk.py", line 77, in GetFriends
    friends_list = CallVK('friends.get', {'user_id' : user_id, 'fields' : 'nickname'}, token)['response']
KeyError: 'response'