How to track down log4net problems:
http://stackoverflow.com/questions/756125/how-to-track-down-log4net-problems
My web application is an ASP.NET MVC one with a separate log4net.config file in the web root. After a lot of googling and hair-pulling I resorted to initializing log4net through code in Application_Start (in Global.asax): protected void Application_Start() { var logConfigFilePath = Server.MapPath(“~/log4net.config”); log4net.Config.XmlConfigurator.ConfigureAndWatch(new System.IO.FileInfo(logConfigFilePath)); } This solved the problem for me and log4net started logging correctly.
Source: asp.net mvc – Application does not log – Stack Overflow