I have a view in my app called LoadingView. For some reason this conflicts with a Swifty Dropbox LoadingViewController. I was getting exceptions that one of my labels was not key compliant with LoadingViewController. this usually means you have an outlet specified in storyboard that no longer exists in your class. I tried uninstalling SwiftyDropbox, cleaning, clearing derived data and re-installing SwiftyDropbox, but still got the error. The only thing that fixed it was renaming my view from LoadingView to something else. Pretty bizarre.