Polymer Serve Changes The Served Javascript Files For Internet Explorer 11. How To Make It Work On Another Web Server?

When testing our polymer 2.01 / webcomponents 1.01 Application on Internet Explorer 11 we found out that it works fine using poyfills when serving the Application with polymer serv

Solution 1:

The problem is solved now, I had to compile the code into ES5, then it also works in IE11 now. You can do that in the build options of polymer.json.