Hello @Emilie Abia,
This is Branislav from the L2 Technical Support team.
The account for the requested user was added as an Admin of organizations that correspond to all Outsight environments.
In order to be able to log in, please ask the user to reset their password by using the "Forgot password?" link on the login screen.
With that in mind, I am tentatively marking this case as resolved. However, please do not hesitate to reach out if there are any issues or you need any help. We would be glad to assist you further.