问web服务中的Log4net

EN

log4net:ERROR An exception ocurred while retreiving stack frame information.
System.NullReferenceException: Der Objektverweis wurde nicht auf eine Objektinstanz festgelegt.
     bei log4net.Core.StackFrameItem..ctor(StackFrame frame)

<?xml version="1.0" encoding="utf-8" ?>
<log4net>  
  <appender name="RollingFile" type="log4net.Appender.RollingFileAppender">
    <file value="Logs/debug.log" />
    <encoding value="utf-8" />
    <appendToFile value="true" />
    <maximumFileSize value="10MB" />
    <maxSizeRollBackups value="2" />
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%date [%thread] %-5level (%class#%method:%line):%message%newline" />
    </layout>
  </appender>
  <root>
    <level value="DEBUG" />    
    <appender-ref ref="RollingFile" />
  </root>
</log4net>

public class ObjectInfo : IObjectInfo
{    
    private static readonly log4net.ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);



    public void DoWork()        {
      Logging.LoggingUtil.InitializeLogging();
      log.Debug("Some message");
    }
}

private const String Log4NetConfigurationFilePath = "log4net-config.xml"; //real path looks somewhat different
public static void InitializeLogging()
{    
  XmlConfigurator.Configure(new FileInfo(Log4NetConfigurationFilePath));     
}