Nlog: Exception.HResult gives unknown exception in internal.txt

[neilmulhy]

NLog version: 4.9.0

Platform: .NET Core 3.0

Current NLog config (xml or C#, if relevant)

<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      autoReload="true"
      internalLogLevel="Warn"
      internalLogFile="c:\temp\internal.txt">

  <!-- define various log targets -->
  <targets async="true">
    <!-- write logs to file -->
    <target xsi:type="File" name="error" fileName="D:\Dev\dotnet\Core\Logs\Logging2.2\error-log-${shortdate}.log"
                 layout="${longdate}|${logger}|${uppercase:${level}}|Type:${exception:format=Type}|HResult:${exception:format=hresult}|${message}" />

    <!-- set up a blackhole log catcher -->
    <target xsi:type="Null" name="blackhole" />

  </targets>

  <rules>

    <!-- Skip Microsoft logs and so log only own logs-->
    <logger name="Microsoft.*" level="Info" writeTo="blackhole" final="true" />
    <!-- Log errors to the error email buffer and error file -->
    <logger name="*" minlevel="Error" writeTo="error" />
  </rules>
</nlog>

Program.cs

```C#
public class Program
{
public static void Main(string[] args)
{
var logger = NLog.Web.NLogBuilder.ConfigureNLog("nlog.config").GetCurrentClassLogger();
try
{
logger.Debug("init main");
CreateHostBuilder(args).Build().Run();
}
catch (Exception exception)
{
//NLog: catch setup errors
logger.Error(exception, "Stopped program because of exception");
throw;
}
finally
{
// Ensure to flush and stop internal timers/threads before application-exit (Avoid segmentation fault on Linux)
NLog.LogManager.Shutdown();
}
}

    public static IHostBuilder CreateHostBuilder(string[] args) =>
        Host.CreateDefaultBuilder(args)
            .ConfigureWebHostDefaults(webBuilder =>
            {
                webBuilder.UseStartup<Startup>();
            })
            .ConfigureLogging(logging =>
            {
                logging.ClearProviders();
                logging.SetMinimumLevel(Microsoft.Extensions.Logging.LogLevel.Trace);
            })
            .UseNLog();
}

**Startup.cs**

```C#
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.Configure<CookiePolicyOptions>(options =>
            {
                // This lambda determines whether user consent for non-essential cookies is needed for a given request.
                options.CheckConsentNeeded = context => true;
                options.MinimumSameSitePolicy = SameSiteMode.None;
            });

            services.AddDbContext<ApplicationDbContext>(options =>
                options.UseSqlServer(
                    Configuration.GetConnectionString("DefaultConnection")));
            services.AddDefaultIdentity<IdentityUser>()
                .AddEntityFrameworkStores<ApplicationDbContext>();

            services.AddControllersWithViews()
                .AddNewtonsoftJson();
            services.AddRazorPages();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
                app.UseDatabaseErrorPage();
            }
            else
            {
                app.UseExceptionHandler("/Home/Error");
                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
                app.UseHsts();
            }

            app.UseHttpsRedirection();
            app.UseStaticFiles();
            app.UseCookiePolicy();

            app.UseRouting();

            app.UseAuthentication();

            ///This is in place of app.UseMvc(... below
            app.UseEndpoints(endpoints =>
            {
                endpoints.MapDefaultControllerRoute();
                endpoints.MapControllers();
                endpoints.MapRazorPages();
            });
        }
    }

HomeController.cs

```C#
public class HomeController : Controller
{
private readonly ILogger _logger;

    public HomeController(ILogger<HomeController> logger)
    {
        _logger = logger;
    }

    public IActionResult Index()
    {
        _logger.LogCritical(new NullReferenceException(), "FATAL Error!");
        try
        {
            throw new NullReferenceException();
        }
        catch (Exception e)
        {
            _logger.LogError(e, e.Message);
        }

        return View();
    }

}

**Log file**

2019-11-18 14:12:26.0470|Logger2._2.Controllers.HomeController|ERROR|Type:System.NotImplementedException|HResult:|The method or operation is not implemented.
2019-11-18 14:15:47.5842|Logger2._2.Controllers.HomeController|FATAL|Type:System.NullReferenceException|HResult:|FATAL Error!
2019-11-18 14:16:09.4641|Logger2._2.Controllers.HomeController|ERROR|Type:System.NullReferenceException|HResult:|Object reference not set to an instance of an object.

- What is the current result?
Nothing is being outputted when ${exception:format=HResult} or ${exception:format=hresult} is used. Is this because it's a number format?
${exception:format=Type} is correctly outputting the exception type.


- What is the expected result?
I expect to see the value of the HResult property outputted. When I debug the error, the HResult is showing as -2147467261. This isn't being outputted in the log.

- Did you checked the [Internal log](https://github.com/NLog/NLog/wiki/Internal-Logging)?
Yes, it says:

2019-11-18 14:08:52.9552 Warn Unknown exception data target: HResult
```

• Are there any workarounds? Yes
• Is there a version in which it did work? 4.9.0 is the first version I've tried to use it

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[304NotModified]

Hi,

You need to add the NLog 4.6.8 package:

<PackageReference Include="NLog" Version="4.6.8" />

NLog.Web.AspNetCore 4.9 uses NLog 4.6.7 indirectly. The HResult option is added in NLog 4.6.8, see https://github.com/NLog/NLog/wiki/Exception-Layout-Renderer

As this is a newer version of NLog and also the same major version (4.x.x), you could safely update the NLog package.

[neilmulhy]

@304NotModified Thanks for the response. I've added this project reference and the warning isn't outputted to the internal.txt file any more but still nothing outputs to the log for:
```C#
${exception:format=HResult}

```xml
    <PackageReference Include="NLog.MailKit" Version="3.1.0" />
    <PackageReference Include="NLog.Web.AspNetCore" Version="4.9.0" />
    <PackageReference Include="NLog" Version="4.6.8" />

[304NotModified]

Please check the version of NLog in your bin folder. Is it really 4.6.8?

[snakefoot]

Also make sure there is an actual HResult. If default value (0 or 1) then it output empty-string (Caters for JsonLayout that will skip attributes that renders nothing)

[neilmulhy]

@304NotModified @snakefoot

Bin has nlog v4.6.8 included:

Exception is throwing with a HResult

Referencing HResult on layout after string placeholder "Res: "

<target xsi:type="Mail" name="key-error-instant-mail">
          <subject>Error on ${configsetting:cached=True:name=WebsiteConfig.ShortName} (${left:inner=${environment:ASPNETCORE_ENVIRONMENT}:length=1}) ${newline}</subject>
          <layout>Res: ${exception:format=HResult} ${longdate} ${level:uppercase=true:padding=5} - ${logger:shortName=true} - ${message} ${exception:format=tostring} ${newline}</layout>
        </target>

HResult isn't outputted after Res: in the email

Package inclusion

  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore" Version="3.0.0" />
    <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="3.0.0" />
    <PackageReference Include="Microsoft.AspNetCore.Identity.UI" Version="3.0.0" />
    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.0.0" />
    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="3.0.0" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Relational" Version="3.0.0" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="3.0.0" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="3.0.0" />
    <PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="3.0.0" />
    <PackageReference Include="Microsoft.Extensions.Logging.EventLog" Version="3.0.0" />
    <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="3.0.0" />
    <PackageReference Include="NLog.MailKit" Version="3.1.0" />
    <PackageReference Include="NLog" Version="4.6.8" />
    <PackageReference Include="NLog.Web.AspNetCore" Version="4.9.0" />
  </ItemGroup>

I'm just working in a demo solution so happy to provide it to you if you can give me upload / email details?

[304NotModified]

Thanks for the detailed info!

A demo would be great! You could create a repo or zip it and include it here. Then we will check it!

[snakefoot]

I see the error:

#if NET45

It should have been:

#if NET_45

[snakefoot]

Created PR #3700