Log4net不给出任何响应或日志

我正在尝试使用log4net将错误写入文件。我没有得到错误，也没有日志文件。我遗漏了什么?

<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />

<log4net>
<appender name="LogFileAppender" type="log4net.Appender.FileAppender">
  <param name="File" value="c:'Temp'testlog4net.txt" />
  <param name="AppendToFile" value="true" />
  <layout type="log4net.Layout.PatternLayout">
    <param name="Header" value="[Header]'r'n" />
    <param name="Footer" value="[Footer]'r'n" />
    <param name="ConversionPattern" value="%d [%t] %-5p %c %m%n" />
  </layout>
</appender>
<root>
  <level value="INFO" />
  <appender-ref ref="LogFileAppender" />
</root>
</log4net>
<appSettings>
  <add key="log4net.Internal.Debug" value="true"/>
</appSettings>

private static ILog _fileLogger = LogManager.GetLogger(typeof(LogHelper));
public static void Error(Exception e)
    {
        _fileLogger.Error(e);
    }