Error 400 when trying to set up on iPhone 6S

[LouiseK]

Hi

i have an iPhone 6s and have been trying to set up but keep getting this message. In looking through the community I see it has come up before but I have tried all the suggestions and nothing seems to work. I have uninstalled the app, log off and log on again and rebooted the phone. Does anyone have any suggestions.

Thanks

Moderator Edit: Clarified Subject.

[MarcoGFitbit]

Hello @LouiseK, it's a pleasure for me to welcome you to the Fitbit Community, I hope you're having an excellent day! 

I'm sorry to hear you’re seeing a “400 error” when attempting to set up your tracker. Usually this error shows up if the app on your phone is out of date. Please update your app to the latest version. Then, attempt setup again. 

I hope this can be helpful, please give it a try and in case you're still seeing the error message, take a screenshot and reply to me with it. Additionally, if there's anything else I can do for you, please let me know.