There are certain situations in which an issue may be created and the initial assignment should be to a user who is a Client license type. During a test I found that I cannot make the initial assignment to the Client because the Client's name does not appear in the dropdown list of names. But if the initial assignment is to a non-Client user, that user can use the Edit function to reassign the issue to the Client user because in this case the Client's name appears in to dropdown. I'm thinking that the inability to assign an issue initially to a Client user is a bug. It doesn't make sense to me that an issue cannot be assigned to initially a Client but then can be reassigned later.