Google Authenticator Update for iPhone Misfires, Causes Login Headaches
Because the app can be used to provide security for other online services, some users who installed the update found that they no longer had the data necessary to log them into services such as Dropbox and Evernote. Re-syncing solves the problem, though it’s obviously a hassle. A Google spokesperson tells us, “We’re aware of this issue and are working to release an updated version as soon as possible.”
Keep in mind that the issue doesn’t prevent you from accessing your Google account. You can access it from a trusted computer and, if you’re an iCloud Backup user, you can simply restore the older version of the app. Google has information for dealing with the issue here.