The Inspector works by injecting some debug code into the running app, so it won't work with FastBoot because the JavaScript is running on the server. That sai

The Inspector works by injecting some debug code into the running app, so it won't work with FastBoot because the JavaScript is running on the server. That said, it should work just fine once the Ember app finishes loading and running in the browser. I would love it if you could file an issue on the Ember Inspector GitHub page with the error you're getting.