Hello Can anyone help??

I am attempting to carry out step 4 on p 89 and when I go to drag and drop the view controller onto my window it will not add. Anyone else have this problem ?

Thank you

It will let me drag a button just not a view controller.

Nevermind, I figured it out:
I was suppose to drag and drop it into my MainWindow.xib window in case anyone has that same problem.