Uncaught ReferenceError: ReactDOM is not defined

Question

So i have Rails applications, i installed react-rails gem, set it up and try to run test application.

Freshly installed, when i tryed to run hello world program, this er

Answer 1

Make sure that you've included react-dom.js. You can add it from CDN or use js toolchain of your choice.

Installing React - using a CDN