In a multiple domain environment, the administrator is unable to add groups/users from another domain. They can successfully add Domain Groups, OUs and Users from the domain where TSE is installed.
The reason that users cannot be added from the other domain is because the Propalms TSE Service Account does not have rights to read objects from this domain.
To correct this problem, you have these options:
Establish a one-way trust
Establish a two-way trust
Give the Propalms TSE Service Account read rights in the domain you wish to add Group, OUs and Users from.