This post shows you how to fix "Cannot find NLog.xsd file" in NLog.config.

<?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"
      xsi:schemaLocation="http://www.nlog-project.org/schemas/NLog.xsd NLog.xsd"
      autoReload="true"
      throwExceptions="false"
      internalLogLevel="Off" internalLogFile="c:\temp\nlog-internal.log">
  <targets>
    <target xsi:type="File" name="fileTarget" filename="..\logs\log.txt"></target>
  </targets>

  <rules>
    <logger name="*" minlevel="Trace" writeTo="fileTarget" />
  </rules>
</nlog>

You need to open Manage Nuget Packages, then install NLog.Schema to your project.

nlog.schema

If you don't install NLog.Schema you will get a warning when you opening the NLog.config file in your Visual Studio that it cannot find the NLog.xsd file.