PGA68
commented
5 years ago Yes. I have the same problem. For this reason, create-react-app does not work in Internet Explorer 11. Object.assign is not supported by this browser.
Fixed for it in my case (only production build) - https://github.com/facebook/create-react-app/issues/7084#issuecomment-494450944
In the generated files there still is lots of ES6 syntax like arrow functions, let, const and property shorthands.
A common Webpack/Babel setup will usually ignore node_modules folder so these will not be transformed and end up causing errors on older browsers.