Starting inspector on localhost:9200 failed: address not available

First time using Bulma and just encountered the error Starting inspector on localhost:9200 failed: address not available while setting Bulma up (https://bulma.io/documentation/customize/with-node-sass/)
Project: https://glitch.com/edit/#!/bulma-test

Does anyone know why this is happening and how I can resolve this error?

I’m not familiar with bulma, but if it’s just a CSS framework then what are you using as a server? If you started with a static site and added a package.json file then we no longer take care of that side for you, so you need to use something like Express. Take a look at https://glitch.com/edit/#!/elated-ocarina for an example setup, which I think does what you need.