Error in tweet_manager.py opener.open(url)

I am getting an error in
response = opener.open(url)
in the Tweet_manager.py file. Basically it looks like the url is returning as not found but when I plug the url generated into chrome I can download the .json generated directly. I think this is related to the user agent in some way but I am not clear on how (Twitter sees the chrome user agent and answers the request). Does anyone have an idea here?

Edit: I did need to rotate the user agent to one not already in my rotation. This did yield a short-term solution for me.