In Feburary we rolled out Firefox Accounts on addons.mozilla.org (AMO). That first phase created a migration flow from old AMO accounts over to Firefox Accounts. Since then, 84% of developers who have logged in have transitioned over to a Firefox Account.

The next step is to remove the ability to log in using an old AMO account. Once this is complete, the only way to log in to AMO is by using Firefox Accounts.

If you have an old account on AMO and have not gone through the migration flow, you can still access your account if the email you use to log in through Firefox Accounts is the same as the one previously registered on AMO.

We expect that the removal of old logins will be completed in a couple of weeks, unless any unforeseen problems occur.

Frequently asked questions

What happens to the add-ons I develop when I convert to a new Firefox Account?

All the add-ons are accessible to the new Firefox Account.

Why do I want a Firefox Account?

Firefox Accounts is the identity system that is used to synchronize Firefox across multiple devices. Many Firefox products and services will soon begin migrating over, simplifying your sign-in process and making it easier for you to manage all your accounts.

Where do I change my password?

Once you have a Firefox Account, you can go to accounts.firefox.com, sign in, and click on Password.

If you have forgotten your current password:

1. Go to the AMO login page
2. Click on I forgot my password
3. Proceed to reset the password

https://blog.mozilla.org/addons/2016/07/21/completing-firefox-accounts-on-amo/