SCRIPT1010: Expected identifier - Production build not running on IE11

[VishalGulati]

I created a new project with create-react-app today. The production build is not running fine on IE11, the console shows following error:

SCRIPT1010: Expected identifier

The line it points to inside my main.js:

{var n=e&&e.__esModule?function(){return e.default}:function(){return e};

The error is after the e.(default) above. My package json is plain:

{
  "name": "sample-app",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "react": "^16.3.1",
    "react-dom": "^16.3.1",
    "react-scripts": "1.1.4"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test --env=jsdom",
    "eject": "react-scripts eject"
  }
}

Strange enough, my dev server works perfectly on IE11 so issue is only with production build. It works well on Chrome as well. Is that I need to have polyfills?

cc @gaearon

[gaearon]

Can you provide a complete project please? Or can you reliably reproduce this with a new project?

[gaearon]

Also. Are you sure you’re not running IE11 in the emulation mode where it emulates IE10 or earlier? Can you screenshot your F12 developer tools please?

[VishalGulati]

You are right @gaearon The emulator opened it in IE7 by default. However, I changed that to latest and got a new error:

SCRIPT5009: 'Set' is undefined

[gaearon]

That's expected: https://reactjs.org/docs/javascript-environment-requirements.html