All classes that need to register are registered by Acrobat. The error means that _create can't be used with that class or interface.
To get an object of that type, call a function that returns an object of that type. If that function returns IDispatch, try to use that type instead. Example:
To get an object of that type, call a function that returns an object of that type. If that function returns IDispatch, try to use that type instead. Example: