NLog failed to parse config file - Target Console not found.

[omerlh]

Hi! Thanks for reporting this feature/bug/question!

Please keep / fill in the relevant info from this template so that we can help you as best as possible.

QUESTIONS are preferred on StackOverflow. You could expect a faster response there (but do include all the info below). Use the tag "nlog" https://stackoverflow.com/questions/ask

For .NET Core users, please check the platform support: https://github.com/NLog/NLog/wiki/platform-support

NLog version: (e.g. 4.4.13) 4.5.11

Platform: .NET Core 2

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="info"
      internalLogFile="internal-nlog.txt">

  <!-- enable asp.net core layout renderers -->
  <extensions>
    <add assembly="NLog.Web.AspNetCore"/>
  </extensions>

  <!-- the targets to write to -->
  <targets>

      <target xsi:type="Console"
          name="String"
          detectConsoleAvailable="false"
          layout="${longdate}|${event-properties:item=EventId_Id}|${uppercase:${level}}|${logger}|${message} ${exception:format=tostring}"/>
  </targets>

  <!-- rules to map from logger name to target -->
  <rules>
    <!--All logs, including from Microsoft-->
    <logger name="*" minlevel="Trace" writeTo="Console" />

    <!--Skip non-critical Microsoft logs and so log only own logs-->
    <logger name="Microsoft.*" maxLevel="Info" final="true" /> <!-- BlackHole without writeTo -->
    <logger name="*" minlevel="Trace" writeTo="Console" />
  </rules>
</nlog>

• What is the current result?
  App start, but no logs are written
• What is the expected result?
  Logs are written to console
• Did you checked the Internal log?

2018-12-06 16:02:45.4642 Info Message Template Auto Format enabled
2018-12-06 16:02:45.4816 Info Loading assembly: NLog.Web.AspNetCore
2018-12-06 16:02:45.5330 Info Adding target Console Target[String]
2018-12-06 16:02:45.5639 Error Parsing configuration from <>/nlog.config failed. Exception: NLog.NLogConfigurationException: Exception when parsing <>/nlog.config.  ---> NLog.NLogConfigurationException: Target Console not found.
   at NLog.Config.XmlLoggingConfiguration.ParseLoggerElement(NLogXmlElement loggerElement, IList`1 rulesCollection)
   at NLog.Config.XmlLoggingConfiguration.ParseRulesElement(NLogXmlElement rulesElement, IList`1 rulesCollection)
   at NLog.Config.XmlLoggingConfiguration.ParseNLogElement(NLogXmlElement nlogElement, String filePath, Boolean autoReloadDefault)
   at NLog.Config.XmlLoggingConfiguration.Initialize(XmlReader reader, String fileName, Boolean ignoreErrors)
   --- End of inner exception stack trace ---
2018-12-06 16:02:45.5652 Warn Failed loading config from <>/nlog.config. Invalid XML?
2018-12-06 16:02:45.5734 Info Found 15 configuration items

• Please post full exception details (message, stacktrace, inner exceptions)
• Are there any workarounds? no
• Is there a version in which it did work?
• Can you help us by writing an unit test? yes

[snakefoot]

Could seem like you are using NLog for NetStandard1.3 (UWP).Console should be available with NLog NetStandard 1.5 + 2.0. Could you verify the file-properties of the NLog.dll in use?

[omerlh]

"NLog/4.5.11": {
        "runtime": {
          "lib/netstandard2.0/NLog.dll": {
            "assemblyVersion": "4.0.0.0",
            "fileVersion": "4.5.11.8645"
          }
        },
        "compile": {
          "lib/netstandard2.0/NLog.dll": {}
        }
      },

This one?

[snakefoot]

Looks good. Are you on some platform (Like UWP, Xamarin, NetNative) where you perform ahead-of-time (AOT) compiling of code to native?

[omerlh]

Not that I'm aware of. MacOS using regular dotnet core.

[snakefoot]

What happens if you perform the configuration using code:

c# var config = new NLog.Config.LoggingConfiguration(); var logconsole = new NLog.Targets.ConsoleTarget("logconsole"); config.AddRule(LogLevel.Info, LogLevel.Fatal, logconsole); NLog.LogManager.Configuration = config;

Maybe for some reason then it might use the iOS-assembly instead of the wanted NetStandard. Or maybe Xamarin-build is doing some linker-tree-shake that removes everything not used directly.

Not an experienced MacOS-developer. Can only say that NLog works just fine with console on NetCore2

[omerlh]

Yep, applying configuration from code is working. So weird...

[snakefoot]

Yep, applying configuration from code is working. So weird...

Then your build-environment is doing ahead-of-time (AOT) compiling of code with linker-tree-shake. You need to modify your build to ignore NLog.dll when stripping away "unnecessary code" .

[omerlh]

Can you help me understand how to do that?

[snakefoot]

Don't know what tools you are using. But maybe this can help:

https://docs.microsoft.com/en-us/xamarin/mac/deploy-test/linker
https://docs.microsoft.com/en-us/xamarin/mac/internals/aot

[snakefoot]

Maybe you can add the following "Skip linking assemblies"-option at Project Options -> Build:

--linkskip=NLog

See also https://xamarinhelp.com/xamarin-linker/ and https://www.mvvmcross.com/documentation/fundamentals/linking

I guess if NLog is ever going to be used on devices where AOT-compile is mandatory without support for reflection (Ex. iOS-Phone-platform) then NLog need to improve on its runtime config-API (Also when using NLog-LayoutRenderers)

[snakefoot]

Created #3039 for NLog 4.6 that should fix the problem with Xamarin Linker removing everything from NLog.dll Allowing NLog.config-files to work without needing to specify --linkskip=NLog

[snakefoot]

@omerlh If you know how to setup a local nuget-package-repository, then you are very welcome to try this pre-release build to see if it works as expected (without using --linkskip=NLog):

https://ci.appveyor.com/project/nlog/nlog/builds/20883080/artifacts (Download NLog.4.5.11.8779-PR3039.nupkg)

[omerlh]

I tried, but look like I can't use this package:

error: Package 'NLog.4.5.11.8779-PR3039.nupkg' is incompatible with 'all' frameworks in project <>.

Also couldn't figure out where should I put --linkskip=NLog.

[snakefoot]

It downloads fine for me:

https://ci.appveyor.com/api/buildjobs/5crbyayfd8o5ojj7/artifacts/artifacts%2FNLog.4.5.11.8779-PR3039.nupkg

[snakefoot]

@omerlh Try rename the package from NLog.4.5.11.8779-PR3039.nupkg to NLog.4.5.11.8779.nupkg (And retry the install)

It might help as someone says here: https://github.com/NuGet/Home/issues/5127 (Have no issues myself using these package-names in VS2017)

[304NotModified]

3039 has been merged, so assume this is fixed. Will reopen if not!

[Shiva799]

I'm facing the issue of config file not loading to the logmanager.configuration. due to this the the config object has not targets in it whereas i have added the rules n targets in the nlog.config file.
Package is Nlog 4.6.1. the nlog.config file is android asset. also the code is portable project

[304NotModified]

I'm facing the issue of config file not loading to the logmanager.configuration. due to this the the config object has not targets in it whereas i have added the rules n targets in the nlog.config file.
Package is Nlog 4.6.1. the nlog.config file is android asset. also the code is portable project

I assume this is https://github.com/NLog/NLog/issues/3283

[snakefoot]

NLog.config can be added as an Xamarin resource, which is automatically deployed but has to be loaded manually:

https://github.com/NLog/NLog/wiki/Explicit-NLog-configuration-loading#loading-nlog-configuration-from-xamarin-resource