Missing native ObjectiveC class after updating Xamarin.Forms and XLabs

I updated Xamarin.Forms to 1.5.1.6471 and XLabs to 2.0.5782 and suddenly I'm getting the following error when it hits the line of code to load a HybridWebView.

Wrapper type 'WebKit.WKUserContentController' is missing its native ObjectiveC class 'WKUserContentController'

The problem is on a physical device running iOS7. It works using the 9.1 emulator.

Any suggestions?