The instantiation of an object should always be done you, the user.
Trying to mess with the serialized data blob in the nib/xib is not
something that you'd want.
In IB3 a lot has changed with regards to defining classes.
If a new class is added it will needs to be instantiated otherwise the
class definition will be lost.
So you need to instantie your new controller, once that's done you can
update it's definition from that point on.
Also I'm not sure if you mean that you can't find it all, if so;
add a NSObject to your project and set it's class to your class,
that's it.
- Eloy