Two-Factor authentication (2FA) works with a 6-digit time-based code (TOTP:Time-based One-Time Password) that only is valid for thirty seconds, so make sure that the time and timezone is correct on all devices including the mobile device with the Authenticator App that generates the TOTP code. More info:

• https://support.mozilla.org/en-US/kb/secure-firefox-account-two-step-authentication
• https://support.mozilla.org/en-US/kb/what-if-im-locked-out-two-step-authentication

Thank you. I know how to use these codes. I use this method with all my accounts, Gmail accounts, Dropbox and everything. I type the codes immediately when they show up on my cell phone - and it has worked every time I used this method, without fail, except this case, with Firefox.

Unfortunately, this doesn't seem the problem.

And what about the logins and passwords? How come that particular space was totally empty when I finally entered my account (using one of the backup codes)? I thought that the same as with Chrome, all the passwords are automatically copied to the new device whenever I enter my account. I suspected this was part of the problem, indicative of the same problem as the one with the codes.

Does the TOTP code work in a browser (Firefox) on the mobile device ?

I have just tried it.

It says: "Open your authentication app and enter the security code it provides." I typed the security code from Google Authenticator, and then received the same response as with the laptop:

Invalid two-step authentication code.

How would you suggest that I should proceed? Should I enter my installed program, cancel the two-step authentication, and then install it again?

I still have six or seven backup codes valid, I don't want to waste them. But I know that if I cancel the 2FA and install it again, I'll get 8 fresh new codes.

Waiting for your advice.

There is another idea I can work with: I can export all the passwords into a file, enter Firefox from another Gmail account of mine, install the 2FA, and see if I can enter my new FF account on my laptop using Google Authenticator.

I've just realized that I see three instances of Firefox on my GA screen in the app - but they all display the same codes every time the code changes, so I guess this shouldn't bother me.

I'll now wait for your advice and proceed according to your suggestion.

Thanks in advance, Eldad

I solved the problem.

I deleted all the entries of Firefox in Google Authenticator, disabled the service in my Firefox account, re-installed the two-step authentication, scanned the code again into Google Authenticator, and now everything is back to normal, working smoothly.

I have one more question, I hope you can help me:

Suppose I now wish to check whether the Firefox codes from Google Authenticator are valid, how can I check one of those codes (in a random check)?

Can you give me an idea?

You can simply logout and login of the Firefox account to verify that the GA app is working properly.

• https://accounts.firefox.com/signin
• https://accounts.firefox.com/settings

Make sure to generate and save the new set of 2FA recovery codes.

You can possibly do this with a new profile. See "Creating a profile":

• https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles

Thank you very much, very good tips.

I have already tried to sign out of my account on the laptop, and then sign in again using Google Authenticator. It worked.

I did save the recovery codes, and also sent them to myself using Gmail (to be on the safe side).

I will read about Firefox profiles and allow myself to revert to you if I have any questions. Thanks a lot!