Black flashes in iOS App Navigation Bar

Question

So I've been getting these black flashes when I segue from one view controller to another in my app. I don't understand what causes this.

Answer 1

It looks like you navigation controller's view backgroundColor is black. Either set it to your desired color, probably white:

navigationController?.view.backgroundColor = .white

or set your view controllers to extend edges, so the view of your view controller extends all the way under the navigation bar:

edgesForExtendedLayout = .all // or .top

Answer 2

Somewhere in the view hierarchy is a view with a black background. Use the view debugger in Xcode to find it, but it could possibly be your window or the navigation controller's view.