Glad it worked out for you.
The reason you was unable to appoint a new Ecclesiarch, might have been because of you not having any Orthodox bishops to appoint. If I remember correctly, only a landed bishop can be appointed (so no landless courtiers). And if you converted to another religion by a random event, you were probably the only one who converted. So all your bishops was probably still Iconoclast. And yeah, the Orthodox Patriarch does not exist from the 769 bookmark, so if you don't use the special "renounce Iconoclasm" decision, you will first have to create it.
Hope that helps!
The reason you was unable to appoint a new Ecclesiarch, might have been because of you not having any Orthodox bishops to appoint. If I remember correctly, only a landed bishop can be appointed (so no landless courtiers). And if you converted to another religion by a random event, you were probably the only one who converted. So all your bishops was probably still Iconoclast. And yeah, the Orthodox Patriarch does not exist from the 769 bookmark, so if you don't use the special "renounce Iconoclasm" decision, you will first have to create it.
Hope that helps!