The CustomErrors element inside an ASP.NET/MVC/Web API Web.config file, is something almost everyone uses somehow, however, many people’s experiences don’t work like they expect. During my years coding primarily ASP.NET MVC, I’ve used the custom errors element again and again. I have also spent countless hours Googling issues and browsing through StackOverflow. This post is an attempt to put down all of the things I have learned on “paper,” so you can avoid having to go through the same pain I did.

Let’s start by discussing what we can do with the customErrors element. When errors happen on your ASP.NET application, you want to tell the user that an error happened. Out of the box, ASP.NET provides an error page often referred to as the “Yellow Screen of Death” (YSoD):

#web.config #aspdotnet