TypeError: string indices must be integers

Hi Guys,
I had just setup my Taxii server and hooked it up to my MISP instance successfully. However on running the python script push_published_to_taxii.py, I am faced with the following error,

Traceback (most recent call last):
File "push_published_to_taxii.py", line 34, in
config["zmq"]["host"],
TypeError: string indices must be integers

Any help will be greatly appreciated...Thank you !