try logging in in Incognito, if that is not working then

try contacting support

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Thanks for coming back to update with your solution, @e-yi!

Delete the github cookie and retry. I still hit a 404 but it was after putting in the 2fa code and still logged me in. Logging in using private browser is only good for a one time session.

I am having the same issue but with firefox. Setup 2fa as either the app or as an sms it shows the image as seen above. I can login if 2fa is disabled or via a private window. Anyone with any thoughts
cheers
tom

Logging in via Incognito mode should not be an "answer" to this question.

Here is my answer: Clear cookies AND restart Chrome.

• My Chrome was awaiting an update, so I restarted Chrome to allow it to update. After this, login worked.
• I also cleared github.com cookies, but this alone wasn't enough, and I'm not sure it was necessary at all. The restart was the key step.

This is Test AnsWer

For me it wouldn't let me in unless I verified my device, but the Verify Device page went to 404. I was looking around, I had to spin up Chrome, on a second machine before I realized it's only in Firefox that this page didn't show. I logged in through Incognito. Which is absurd. I only found this on Google using a bunch a keywords, now I'm here to: WTF amirite? 😕

Solution for Yandex Browser (Chrome based browser from Yandex).
You don't need to use Incognito mode, just install some cookie management add on (like Cookie-Editor or something like that), go to github.com and delete all cookies for that domain. Refresh page. Try sign in again. It worked for me, 2FA code request shown.
I think that the problem github cookies, stored in browser before 2FA activation.

Same in russian: решение для Яндекс.Браузера.
Не нужен вам режим инкогнито, просто порежьте куки github.com каким-нибудь менеджером куки (типа Cookie-Editor или что-то в этом духе) или грохните все куки (но тогда вылетит авторизация на всех других сайтах) и попробуйте войти снова. У меня сработало, после ввода логина и пароля появилось окно ввода кода 2FA.
Очевидно, проблема была в старых куки, сохраненных в браузере ещё до активации двухфакторной авторизации.

Hi how are you???help me please 404 page not found github my gmail amangeldijan0503@gmail.com please

Tengo el mismo problema, puedo acceder a mi cuenta pero no es visible mis proyectos para otras personas, y creo que desde que añadi el 2FA sucedio eso alguno puede ayudarme