Anybody come across this problem? Unable to activate constraint with anchors <NSLayoutDimension:0x28276bb00 "_UINavigationBarTitleControl:0x155327a70.height"> and <NSLayoutDimension:0x28281d840 "UILayoutGuide:0x28043e300'TitleViewGuide(0x14ff9ee00)'.height"> because they have no common ancestor. Does the constraint or its anchors reference items in different view hierarchies? That's illegal. Who can tell me why？ Or the solution