Comment by superkuh

I don't get any errors in my JS browser console. It just tries to load the JS files and apparently they don't run.

[12:03:18.699] GET https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/13ce36fef98a3f4... [HTTP/1.1 200 OK 227ms] [12:03:19.483] GET https://code.ffmpeg.org/.within.website/x/xess/xess.min.css?... [HTTP/1.1 200 OK 611ms] [12:03:19.485] GET https://code.ffmpeg.org/.within.website/x/cmd/anubis/static/... [HTTP/1.1 200 OK 839ms] [12:03:19.486] GET https://code.ffmpeg.org/.within.website/x/cmd/anubis/static/... [HTTP/1.1 200 OK 391ms] [12:03:19.487] GET https://code.ffmpeg.org/.within.website/x/cmd/anubis/static/... [HTTP/1.1 200 OK 368ms]

For clarification I am using a version of Firefox from about 2015. But this version of Firefox does work with the meta-refresh based Anubis option.