LogManager.configuration is null

Question

I've added NLog using nuget to a project and added NLog.config. I'm running the debugger and getting a NullReferenceException due to the fact LogManager.Configuration is null:

LogManager.Configuration.AddTarget("sentinel", sentinalTarget);

This line of code runs in a static constructor.

• NLog.config is located in the project root alongside the web.config.
• This occurs in visual studio debugger
• NLog.config property "Copy to output directory" = "Copy Always"
• I updated NLog.config throwExceptions="true" and at runtime LogManager.ThrowExceptions was false so I suspect an issue with the config
• Tried removing the targets with name: viewer, DbWin and their associated rules

NLog.config contents:

<?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"
      throwExceptions="false">

  <variable name="appName" value="YourAppName" />

  <targets async="true">
    <target xsi:type="File"
            name="default"
            layout="${longdate} - ${level:uppercase=true}: ${message}${onexception:${newline}EXCEPTION\: ${exception:format=ToString}}"
            fileName="${specialfolder:ApplicationData}\${appName}\Debug.log"
            keepFileOpen="false"
            archiveFileName="${specialfolder:ApplicationData}\${appName}\Debug_${shortdate}.{##}.log"
            archiveNumbering="Sequence"
            archiveEvery="Day"
            maxArchiveFiles="30"
            />

    <target xsi:type="EventLog"
            name="eventlog"
            source="${appName}"
            layout="${message}${newline}${exception:format=ToString}"/>

    <target xsi:type="NLogViewer"
            name="viewer"
            address="udp://127.0.0.1:9999"/>

    <target xsi:type="OutputDebugString" name="DbWin" layout="Log4JXmlEventLayout">
      <layout xsi:type="Log4JXmlEventLayout" />
    </target>
  </targets>
  <rules>
    <logger name="*" writeTo="default" minlevel="Info" />
    <logger name="*" writeTo="eventlog" minlevel="Error" />
    <logger name="*" minlevel="Debug" writeTo="viewer" />
    <logger name="*" minlevel="Trace" writeTo="DbWin" />
  </rules>
</nlog>

Update
I discovered the source. The issue occurs only when running unit tests. Running the full application (web app) the issue is not there. I copied the NLog.config file to the unit test home directory. The issue is still there when running unit tests.

Answer 1

• Copy NLog.config to the Test projects top level folder
• Add DeploymentItemAttribute to test classes (more info)

Like this:

[TestClass]
[DeploymentItem("ProjectName\\NLog.config")]
public class GeneralTests

Alternatively, you can load the configuration programmatically:

LogManager.Configuration = new XmlLoggingConfiguration(@"c:\path\to\NLog.config")