Community Moderator Alumni are previous members of the Moderation Team, which ensures conversations are friendly, factual, and on-topic. Moderators are here to answer questions, escalate bugs, and make sure your voice is heard by the larger Fitbit team. Learn more
@TheLetterTwo Welcome to the Fitbit Community! Thanks for reporting the situation you are experiencing with your One not setting up. Thanks for providing the error message you are getting.
In this case, to prevent those errors from happening; you need to update the Fitbit app on your mobile device. Once you have the latest Fitbit app version you should try the set up process once again. Your tracker should set up correctly.
You could also try using a computer to set it up.
Hope this helps. Keep me posted! 
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Community Moderator Alumni are previous members of the Moderation Team, which ensures conversations are friendly, factual, and on-topic. Moderators are here to answer questions, escalate bugs, and make sure your voice is heard by the larger Fitbit team. Learn more
@TheLetterTwo Thanks for your reply and for trying the provided steps in order to sort this out.
I went ahead and created a case with customer support in your behalf so you can get further assistance. Please keep an eye on your email inbox for next steps.
Keep me posted!
Best Answer