Angular IE11 not working. Getting SCRIPT1002 Syntax Error

For others running across similar issues:

Angular 8 has made the default target es2015 instead of es5

You'll want to create a tsconfig.es5.json so that you only run on es5 in development mode, but more information on that can be found here: https://github.com/angular/angular-cli/issues/14455

You'll also want to uncomment the polyfills in polyfills.ts depending on what you are using.

For others and for the asker:

Then, you'll want to add a flag to zone.js

Add import './zone-flags.ts'; before import 'zone.js/dist/zone'; then create the zone-flags.ts file in the same directory as the polyfills.ts.

In the zone-flags.ts file add the following line:

(window as any).__Zone_enable_cross_context_check = true;

Hopefully after that everything is working! If you followed the link above,

Execute: ng serve --configuration es5 to run your project in IE in development mode.

Update

It looks like angular actually has documentation on this: angular.io/guide/deployment#fallback

Look for "Local development in older browsers" and then "Configuring serve for ES5"

The issue is caused by Angular 8's differential loading process.