Hello Obillwan. This happens because Firefox requires verification through your current email before allowing changes to account details. If you no longer have access to that email, the system will still request a confirmation code from it for security reasons. You can try: Checking if you are logged in on another device and changing it from https://accounts.firefox.com Contacting Mozilla Support for assistance in account recovery If access to the original email cannot be restored, changing the email may not be possible, and creating a new account could be required, what i recommend is contacting Mozilla user support and tell them what happened and give them out proof that the account is yours. they may then give back your account.