Attempting to login an account that isn't from the known location.

Signing an account in from the united kingdom when the account is normally signed in from germany or america causes the app to display the error message as shown in the image.

The problem is the mobile app doesn't understand how to ask for the email verification for an unknown location, The error message is displayed and you are left clueless but within the account that was attempted to login does get an email about an unknown location login but the mobile app shows just a "login failed" message.

Repeat by having a friend sign into the mobile account from your account gathering you are not in the same location.