Hmm.. Not sure what is causing your problem. I was testing the software on Firefox (69.0) while writing it and it works just fine. Maybe you're blocking JS or something?

I would appreciate if you could open a more detailed issue on the GitHub repository at: https://github.com/lubeskih/enigma-emulator.

Thank you!

Also works for me on Firefox 68.

Work for me on Firefox 69.0