I’m not exactly sure what’s going on here, but it seems to be with Twitter’s API not connecting to the script. A few other people in the comments seemed to be having this general problem and it might have to do with your keys and tokens not matching up. Here’s a response I wrote to someone having this problem: https://medium.com/@lilysun/hello-daniel-c6cbbad8f0ad#.cg0ftf5hb
If that doesn’t work, I would start fresh. Make a fresh Twitter app, download a fresh script, and follow the tutorial really closely. Let me know if these work.