My bad, this is likely WebGL2 support, as others have pointed out. Now I show a message on the canvas area if that's the case.

I wasn't expecting it to get quite this popular, so hadn't handled this (rather major) edge case.

Same here. I blame the popularity of Next.js. More and more of the web is slowly becoming more broken on Firefox on Linux, all with the same tired error: "Application error: a client-side exception has occurred"

Works fine on Firefox on Linux for me.

For me too.

Next.js was never really broken for Firefox for Linux in my experience.

Through some "hidden" settings, disabling JS, and proably quite many plugins can brake things.

The only thing which tends to be often "broken" for FF in my experience is often CORS and Mic/Camera APIs, ironically in case of CORS 100% because of bugs in non standard compliant websites and for Mic/Camera it's more complicated but most common websites simply refusing to work with FF without even trying (and if you trick them into believing it's no FF often working just fine...).

It is possible that your machine does not yet support WebGL2.

Check here : https://get.webgl.org/webgl2/

Or that you've blocked it (some sources recommend this to avoid fingerprinting so various extensions and privacy configuration receipes do it).