I'm sorry for the delay and trouble. To confirm, did you recently reset your Nest Protect to its default settings? Are you using the same account in the Nest app? Were there changes made with the setup, settings, and/or app of the Nest Protect? Also, is this your first time receiving this message?
Since this thread hasn't had activity in a while, we're going to close it to keep content fresh. Feel free to submit another post, and provide as many details as possible so that others can lend a hand.