Nope, it's not an activation code required message, this is a problem with the OS that prevents users from logging into the Microsoft Account on the new phone.
The Fix: hard reset the phone.
Go to Settings > About > Reset My Phone.
After the reset, you should be able to log into your account
154 people were helped by this reply
Did this solve your problem?
Sorry this didn't help.
Great! Thanks for marking this as the answer.
How satisfied are you with this reply?
Thanks for your feedback, it helps us improve the site.
How satisfied are you with this response?
Thanks for your feedback.