异常：无法识别的配置节log4net

解决方案：

You need to declare the log4net section:

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

Take a closer look at the documentation which explains the necessary things to do.

原文地址：https://www.cnblogs.com/herizai/p/7206053.html