This error message is displayed if you: 1. entered an incorrect code or 2. if your device was not recognized as a 'known device' and you previously entered an incorrect password. 

1. Therefore, please check: (a) whether you have entered the code correctly (and without spaces) and (b) whether a newer code has been sent and try entering it as well.
   
   
2. If this does not work, check your password, perform a page refresh and enter the correct password (in this case - since your device was not recognized as a 'known device' - the password was only verified after entering the code for security reasons). If you have forgotten your password, please contact your administrator.