Xamarin.iOS - failed to load ObjCRuntime.Runtime

Oct 29, 2017 | 1 min read | C#, Xamarin, iOS

I’m updating my Golden Ratio Calculator app to be ready for iPhone X.

The app is built using Xamarin Forms. After updating the packages and building the solution, I tried running it on my iPhone 7 with iOS 11. This error was the result:

Xamarin.iOS: Fatal error: failed to load the class 'ObjCRuntime.Runtime'

After getting zero hits on Google, I deleted the bin and obj folders and rebuilt the app.

Success, as if by magic.

The old adage from the IT Crowd still holds true.