React 16: Warning: Expected server HTML to contain a matching
in

Question

Since upgrading to React 16 I get this error message:

warning.js:33 Warning: Expected server HTML to contain a matching <div> in <body>.

What is generally causing this error message and how can it be fixed?

Jay Hu · Accepted Answer

If you use ReactDOM.hydrate to start web application, you will see this warning.

If your application does not use server-side rendering (ssr), please use ReactDOM.render to start.

React 16: Warning: Expected server HTML to contain a matching <div> in <body>