Minimal implementation of `Package` to register and provide an implementation of `IVsLanguageInfo`.

ExamplePackage.cs

using System;
using System.Runtime.InteropServices;
using Microsoft.VisualStudio.Shell;
using IServiceContainer = System.ComponentModel.Design.IServiceContainer;

[PackageRegistration(UseManagedResourcesOnly = true)]
[InstalledProductRegistration("#110", "#111", "1.0")]

[ProvideLanguageService(typeof(ExampleLanguageInfo), "Example", 100)]
[ProvideLanguageExtension(typeof(ExampleLanguageInfo), ".e1")]
[ProvideLanguageExtension(typeof(ExampleLanguageInfo), ".e2")]

[Guid("your guid here")]
public class ExamplePackage : Package
{
    private ExampleLanguageInfo _languageInfo;

    protected override void Initialize()
    {
        base.Initialize();

        _languageInfo = new ExampleLanguageInfo();
        ((IServiceContainer)this).AddService(typeof(ExampleLanguageInfo), _languageInfo, true);
    }
}

Can you please provide detailed assembly version info?