Log4net does not write the log in the log file

Solution 1:

Do you call

log4net.Config.XmlConfigurator.Configure();

somewhere to make log4net read your configuration? E.g. in Global.asax:

void Application_Start(object sender, EventArgs e) 
{
    // Code that runs on application startup

    // Initialize log4net.
    log4net.Config.XmlConfigurator.Configure();
}

Solution 2:

Use this FAQ page: Apache log4net Frequently Asked Questions

About 3/4 of the way down it tells you how to enable log4net debugging by using application tracing. This will tell you where your issue is.

The basics are:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <appSettings>
        <add key="log4net.Internal.Debug" value="true"/>
    </appSettings>
</configuration>

And you see the trace in the standard output

Solution 3:

As @AndreasPaulsson suggested, we need to configure it. I am doing the configuration in AssemblyInfo file. I specify the configuration file name here.

// Log4Net Configuration.
[assembly: log4net.Config.XmlConfigurator(ConfigFile = "log4net.config", Watch = true)]

Solution 4:

Also, Make sure the "Copy always" option is selected for [log4net].config