I really don't believe twitch is blocking Firefox. Check your add-ons, clear cookies, etc.

Firefox is actually one of the recommended browsers, if you were to click on that link. Twitch just has some issues sometimes

I just logged in, no issues, probably check your extensions. Mine are minimal, includes uBlock, regular Firefox updated to latest.

Differing experiences might mean that Twitch is performing A/B testing on blocking Firefox.

Seems to be working OK for me on FF with Ublock and Privacy Badger running.

I had this come up when I was using a locked down version of FF.

Basically what happened was the security settings were not allowing Twitch the access it required.

Once I went through and allowed access it worked fine.

Anecdotally, it's still working for me. Using uBlock Origin, logged in with a Twitch account.

What does the "recommend browser" link point to? Is it this page, which lists Firefox as a supported browser? https://help.twitch.tv/s/article/supported-browsers?language=en_US

You need to disable resist fingerprinting. It's annoying, but you can reenable it after you've logged in

Change user agent. Log in, opting to stay logged in for 30 days. Change user agent back.

That's my routine with LibreWolf.

I also believe they don't like a particular security setting present on FF based browsers, though I don't recall off the top of my head which one.

Stop using recommended when you mean required FFS.

This is a cookies/tracking issue, not a Firefox issue.

If you set it to allow tracking, it will let you login, and you can disable tracking again after and it will remember you.

Now that is a long password lol

It was doing this to me a while back. Are you using a VPN or using an ad-blocker specifically for Twitch's embedded stream ads? (e.g. TTV-LOL-Pro) The latter work by using proxies and so I think trigger the same sort of effects. Disabled it and it worked fine. It also happened on a Chromium-based browser when I tested it out.

When I got that message I just refreshed the page and tried logging in again and it worked.

Everyone boo this service! BOOOOOOOOOOO!

As if I needed more reason to not go to Twitch. 😂

But it actually works fine for me. Firefox beta 122.0, uBlock Origin and Consent-O-Matic installed.

Does it still let you sign in? I am currently signed in and it works

I had to disable an extension to log in last time I got this message. Alternatively, force refresh the page.