This is because you didn't tell log4net to read config from your log4net.config
file in your assembly attribute:
see the Configuration Attributes in official document:
// Configure log4net using the .config file
[assembly: log4net.Config.XmlConfigurator(Watch=true)]
// This will cause log4net to look for a configuration file
// called TestApp.exe.config in the application base
// directory (i.e. the directory containing TestApp.exe)
// The config file will be watched for changes.
Change it to following should work:
[assembly: log4net.Config.XmlConfigurator(ConfigFile="log4net.config",Watch=true)]
Or if you prefer a single .config file, then keep the attribute and move the configruations from log4net.config
to Web.config
.