RazorLight with .Net Core 2.0 WebApi System.TypeLoadException

Question

I have followed the following link to use a Razor style syntax with my email templates;

Microsoft Code Razorlight Tutorial

I have implemented a static helper class for getting my templates.

    public static string GetTraderApplicationDeletedTemplate(Trader trader)
    {
        string templatePath = $@"{Directory.GetCurrentDirectory()}\EmailTemplates";

        IRazorLightEngine engine = EngineFactory.CreatePhysical(templatePath);

        string result = engine.Parse("TraderDeletedEmail.cshtml", trader);

        return result;
    }

However, when debugging the engine.Parse method is throwing a System.TypeLoadException with no further detail?

Now the templatePath is valid (as is the file name .cshtml)? Does anyone have any ideas on what could be causing this error?