I just updated my Xcode ver from 7.3 to 8.0 and some buttons borders disappeared.
The code looks fine, so I really don't know what happened to the layers.
btw - in some other controllers I can see the layers borders.
self.button.layer.borderColor = borderColor.CGColor;
self.button.layer.borderWidth = 2;
self.button.layer.cornerRadius = CGRectGetHeight(self.button.frame) / 2;
I think problem in it:
CGRectGetHeight(self.button.frame) / 2;
When you set corner i think height button don't have value or value to larger border will don't show. You can try change it to
self.button.layer.cornerRadius = 15;
If work, I think you can check your logic and set it when height button get right value.