Bought used XBox One from ebay - can't exit preview group to activate for development

Ok, it is resolved and working now.

Thank you.

Thanks for the post! We handed this information over to the appropriate team, and your console should be removed within 24-48 hours. If you continue to run into any snags along the way, or your console does not appear to be removed after 48 hours, please
post back to let us know!

Something else to bear in mind is that if you are a part of the Xbox preview update program you must quit that before you can use the dev mode.

support.xbox.com/.../developer-mode-activation-app-faq

I'm part of the Xbox One Preview program. Can I download the Developer Mode Activation App?

If you’re part of the Xbox One Preview program, you’ll need to leave that program before you can join this one. If you decide that you don't want to get Preview updates anymore, you can opt out from the Xbox Preview Dashboard app.

Here's how to remove your console from the Xbox Preview program:

1. Open the Xbox Preview Dashboard app.
2. Select Registration.
3. Under Manage flights, select Change.
   Note If you have more than one console in the program, you can change their statuses by using
   Manage other consoles.
   
4. Under Manage programs, select Remove, and then select Submit. You'll be prompted to select a reason for leaving.
   

If you run into any issues, post in the private Xbox Early Access forums for help.

Note It will take one business day after requesting to be removed from the Preview Program for your request to process. Until then, you will not be able to download the app, and your console's status will show as Pending.

Hi

The exact same thing has happened to me. I bought one from ebay and now I can't cancel my subscription

Hello TheNinthBit.

You're good to access the
Xbox One Update Preview forum now. Head on over there and if you're still seeing Group Not Found when you try to access the forum, create a new thread letting us know.

Be sure to keep in mind that the New Xbox One Experience is part of the Update Preview program which gives users access to updates before they are publicly released. Because the NXOE is still in development you may still run into issues, which you can report
through the Xbox One preview app or through the Xbox One Update Preview forums which will help the with the development before official release.

For a full run down of how the Preview Program works head over to
this FAQ.

Cheers!