I created a new project with the VS2017 wizard at New Project->Visual C#->Cross-Platform->Mobile App (Xamarin.Forms) with a Code Sharing Strategy of ".Net standard" on VS2017 version15.6.0 on windows 10. I add the Urhosharp nuget package version 1.8.91 to all four projects in solution.
The shared project has a warning on the Urhosharp dependency.
Package 'UrhoSharp 1.8.91' was restored using '.NETFramwork, Version=4.6.1' instead of the project target framework '.NETStandard, Version=v2.0'. This package may not be fully compatible with your project.
Despite this dependency warning, the UWP and Android versions run well in the androidSimulator and local windows machine.
The iOS has a runtime timeout error at launch of the app in the iPhoneSimulator but not on a connected iPhone.