Ghoul Disciplines
 

When i am creating a Ghoul, I am only being able to select the physical discipline associated with the clan the Ghoul is attached to. (Vigor for Nosferatu, Resilience for Ventrue etc.) Now I know the rules for learning Disciplines both in clan and out of clan for ghouls, yet I get redletter errors whenever I try. Why is this and how can I fix it?

Thanks for any help.