title: Could not create plugin of type class org.apache.logging.log4j.core.appender.RollingFileAppender for element RollingFile
body: <p>I want my application to output logs to a the logfile in a  user's home directory.
  Therefore I have configured the <code>log4j2.xml</code> file as below:</p>
  
  <pre><code>&lt;Configuration&gt;
  &lt;Properties&gt;
      &lt;Property name="logfolder"&gt;/${sys:user.home}/xx/log/ff&lt;/Property&gt;
  &lt;/Properties&gt;
  &lt;Appenders&gt;
      &lt;RollingFile name="user_file" append="true" fileName="${logfolder}/logxyz.csv" filePattern="${logfolder}/old/$${date:yyyy-MM}/service-%d{MM-dd-yyyy}-%i.csv.gz"&gt;
          &lt;CsvParameterLayout format="Default" nullString="" charset="UTF-8"/&gt; 
          &lt;Policies&gt;
  </code></pre>
  
  <p>I can see the logs in the specified folder, however, some errors are displayed in the console:</p>
  
  <pre><code>ERROR Could not create plugin of type class org.apache.logging.log4j.core.appender.RollingFileAppender for element RollingFile : java.nio.file.InvalidPathException: Illegal char &lt;:&gt; at index 2: /C:\Users\xx/yy/log/abc/def.csv java.nio.file.InvalidPathException: Illegal char &lt;:&gt; at index 2: /C:\Users\xx/yy/log/abc/def.csv
  at sun.nio.fs.WindowsPathParser.normalize(WindowsPathParser.java:182)
  </code></pre>
  
  <p>The error seems to be related to parsing the windows files system, but I've got no idea how to go about this. Will appreciate any directions. I am developing on Windows 10, but the application logging should be cross-platform.</p>