Reason why your seeing that is because that user doesn’t have ‘admin’ rights on the UC Server. From that prompt on the physical Server itself, you can only log in using the default “admin” user account that on the UC Server. You set that password when you install the server. If you don’t know what that password is, let me know and I can show you how to default it. It will require you to restart the application server service.
Other option is to log back into the physical server as the service account and then assign that user account you logged in with ‘admin’ privileges and then that login will work. If you don’t know how to do this let me know and I can provide steps.