A change in Xamarin.Forms 1.2.x requires that assemblies containing custom renderers must be loaded before Forms.Init() is called. This seems to affect only iOS projects.
As XamSvg for Xamarin Forms contains a custom renderer in its own assembly, it is affected by this change. The result is an iOS demo which does not display anything.
A workaround is to force the loading of the assembly by using it before Forms.Init() like this:
SvgImageRenderer.InitializeForms();The SvgImageRenderer class was private, so you'll have to update the XamSvg Forms nuget to the prerelease version to use this workaround.
The full AppDelegate will look like this:
public class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
public override bool FinishedLaunching(UIApplication app, NSDictionary options)
//Required since Xamarin.Forms 1.2.x
//To be registered, the lib containing the custom renderer must be loaded before Forms.Init()
return base.FinishedLaunching(app, options);