xamarin - Could not resolve type with token 0100000f

Question

I get this error when running ios in xamarin forms. How can I resolve this?

System.TypeLoadException: Could not resolve type with token 0100000f

[Register("AppDelegate")]
public partial class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
{

    public override bool FinishedLaunching(UIApplication app, NSDictionary options)
    {
        global::Xamarin.Forms.Forms.Init();
        LoadApplication(new App());

        return base.FinishedLaunching(app, options);
    }
}

Answer 1

The TypeLoadException with a number token (instead of a type name) usually indicates that the assembly used at runtime is different than the one used at compile time.

In the Xamarin.Forms case, that usually means you have different projects in your solution referencing different versions of Xamarin.Forms

make sure all of your projects are aligned in version, and that you do not have stale ones lying around (do a git clean -xfd, or remove the packages folder, restore the nugets, and make sure there's only one XF version pulled from nuget.org)