[Splines]

I realize this is probably not helpful for you, but it works on my machine. FF 65.0.1 on Win10.

[mirimir]

Thanks. I have Firefox 60.3.0esr (64-bit) in Debian jessie. So maybe it's the age, or that I block WebGL. Or maybe spoofing referrer. Or blocking local storage. Or something else about NoScript.