This bug has been driving me nuts since I started using Xcode (4.6.3). Whenever I try to link a Storyboard item to my code, I get the error:
Could not
In case anyone is still frustrated by this, there's a trick to get things working.
What I do is manually enter an outlet into my class, for example: @IBOutlet weak var someView: UIView!, and drag from the code to the view in IB or storyboard. After this, I am able to drag from IB / Storyboard to my class to make connections, assistant editors recognizes the class in "Automatic", etc...
Works every time.