The TIC server is set up on a machine that is in a separate domain from the one our users are currently on. Let's call them Domain A and B. The TIC server is on Domain A and the users are on Domain B.
When a user is added to the TIC server, as an Active Directory User for Domain A, it is allowed and an Intelligence Central connection can be added as an Active Directory User, as long as the user is logged onto the server and in Domain A.
However, if a user tries to make an Intelligence Central connection as an Active Directory user on their own machine, in Domain B, it will not allow the connection. It only has the option to use 'Windows Authentication', not Active Directory. So, they can not enter another domain before their user name. Additionally, the user name field won't accept \'s or non-alpha characters for domains.
Plus, now that the Active Directory user is on the server, it says they already have a login and must use Active Directory authentication.