Why won't my Duo passcode work?

Version 7

    Duo Security is a method of strong authentication that allows a third party service to send a set of validation codes known as passcodes to your device. There are a number of reasons one of those codes may not work.


    • You might have already used the validation code.


    The screen will tell you which code it is expecting next from the list of codes.

    next expected code.png
    • You might have requested a new set of validation codes.


    This invalidates all the codes in all of your earlier sets.