Command failed due to signal: Segmentation fault: 11 (xcode 7)

[djaygit]

I updated my xcode 6.4 to xcode 7 (swift 2) and now I'm getting this error in my swift project. After few tries i found out it was happening because of

func containerView() -> UIView {
return self.view
}
which is a protocol of UIViewControllerTransitionCoordinatorContext , if i remove that function then it says my ViewController does not conform to this protocol UIViewControllerTransitionCoordinatorContext . xcode 7 is suggesting me to change the function to

func containerView() -> UIView? {
return self.view
}
and after that it suggests me to delete the question mark.