To avoid this issue, make sure you've logged into all your 2factor accounts, and have the new Authenticator QR code ready -before- updating. eg. For Google acc

To avoid this issue, make sure you've logged into all your 2factor accounts, and have the new Authenticator QR code ready -before- updating. eg. For Google accounts: 'Move to a Different Phone' at https://accounts.google.com/b/0/SmsAuthSettings https://accounts.google.com/b/0/SmsAuthSettings