Got an interesting node.js warning on the server while rendering React components. After a little research and this helpful Stack Overflow Question that described the problem being due to adding event listeners in the componentWillMount rather than the componentDidMount. I didn’t realize the distinction that componentWillMount will run while rendering on the server. In any case, this is pretty useful and interesting information that helps me understand how to use componentWillMount and componentDidMount when building components that get rendered on the server. I hope this helps someone out there.