Angular 2+: IE 11 Unable to get property 'call' of undefined or null reference

Even the with above polyfills included, you may still be using a feature that is not supported in IE. Instead you might try this:

 import 'core-js/shim';

This will include ALL of the polyfills (which doesn't really add that much to your bundle anyway). At the very least, this will help to eliminate that polyfills are the problem.

The source for reference: https://github.com/zloirock/core-js/blob/master/shim.js

Good luck!

This error only happens when running ng serve, and will not occur in a production build, so the issue is non-critical, and has a workaround, as follows:

Workaround: When this occurs, close your browser, restart Angular-CLI dev server, and reopen the browser to your app. (You don't need to clear cache, or anything else.)

This sometimes occurs in one testing environment and not others.

Per this thread, github.com/jakehockey10 says:

I'm having this issue only after a live-reload occurs with the Developer Tools open. No issue with Chrome and Firefox, but if I have the Developer Tools open in IE11 and save a change to my typescript, nearly 100% of the time, I get these errors upon reload.

Also, Angular 6 is now in full release, and uses a new major version of Webpack. I haven't tried it yet, but would be good to know if someone has tried resolving the issue by upgrading.