Visual Studio Xamarin - Problem building realease iOS project with webservice

I'm experiencing an error when trying to build a release iphone app and I've noticed it has to do with Web Service. It only happens when I add a Web reference.

The target framework is .NET Standard 2.0 and I'm using Visual Studio 2017.

The error is the following:

1>SGEN : error : Não foi possível carregar arquivo ou assembly 'mscorlib, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e' ou uma de suas dependências. Falha na validação de nome forte. (Exceção de HRESULT: 0x8013141A)

It happens with all the projects I've tested. Has anyone gone through this as well?

I've created a Xamarin Web Forms project and didn't add any code on it, just configured all the info in order to build the app. It worked fine. I've added a Web reference to consume my webservice and it gave me that error when I tried to build the project. Is it a problem with the System.web.service.dll?

System.web.service does not exist for NetStd2, you can not arbitrarily add manual assembly references (especially ones that are based off of the .Net Framework).

You can add a reference to the pre-existing Xamarin.iOS and Xamarin.Android versions within the platform native projects (not .NetStd2 ones).

• Xamarin.iOS References:

• Xamarin.Android References:

And then access it from .NetStd2 via a Forms' dependency service:

• Xamarin.Forms DependencyService Introduction