I'm trying to add an Apple individual developer account to Xcode and keep getting this error. Everything was working fine 12 hours ago and now suddenly adding is no longer possible.
Unable to add Apple ID to Xcode
Were you able to solve this?
Hello Fahad,
My name is Nathalie, and I am a senior Advisor with Apple Developer Program Support. I have been given your case for review, and I will be your contact for this request from here on.
I’m sorry to hear that you are not able to proceed with your project with your device as it is already registered on a different membership. However, the error message received is expected. I also reviewed your membership, and could not find any Mac registered.
I understand that you deleted accounts from the organizer as well as from the key chain. However, please note that the issue is that the device is registered on a different membership. As a result, it is on the membership where it is already registered that it must be deleted.
Please, use a different device, as instructed, or remove the device from the existing Apple Developer Program membership.
This is the reply i got from apple.
Also being discussed here : https://developer.apple.com/forums/thread/708437