Editor not working on latest Firefox.

[SampsaKaskela]

I try to use monaco-editor with latest Firefox but editor is not working. Demos also don't work on Firefox. I have Firefox version 60.0.1 (64-bit). I'm not completely sure if this is an issue with this component or with webcomponent polyfills in general.

Here are the error messages from Firefox console when trying to run demos. I don't get any errors in my environment but editor is still not displaying.