Encounted such error in VS after I update the xamarin at Mac side.Here is the solution for u to reference:
Open VS ->Tools->Options->Xamarin->IOS Settings
Click ‘Check Now‘ to update VS side‘s Xamarin part to same version with Mac side
Your build host version of Xamarin.IOS (release NO.)is too recent to work with the IOS designer
原文：http://www.cnblogs.com/weeky/p/3966414.html