A user will get this error message when an admin tries to add a user who belongs to other IAM organization or who owns another IAM organization. The term 'organization' here refers to a user who has created an account for using any of the products of a company. This means by creating an account, this user has created an organization. The test cases along with solutions have been elaborated as follows:
Solution: You can ask that user to close the account and request the System Administrator to add this user.
Solution: Either he has to create a new mail id and register while signing up for the second application, or he can contact the support team requesting them to merge accounts so that he can use both the applications with the same mail id.
Solution: Ask X to dissociate Y so that the Administrator can add Y.