mern-crud | simple records system using MongoDB , Express.js , React.js | Runtime Evironment library

This error usually happens when a server's request (Express server) doesn't know how to render the response. Express, in this line, needs to know the extension of the file, or the default view to render the correct response.

With React (in a SPA), you don't need to set a default view engine because it will always render your index.html (which contains your React app), no matter what url you use, and since you are using React Router, the routing is always handled by index.html, and then the router can render the correct route. So what you need to do is to respond with the correct file and extension.

In your ./bin/www try adding this: