ASP.NET Application hosted on IIS7 that is ignoring custom errors and falls back to IIS errors

Question

I have a C# web forms ASP.NET 4.0 web application that uses Routing for URLs for some reason custom errors defined in the system.web section of my web.config is entirely ign

Answer 1

To disable the IIS error messages you have to set

  Response.TrySkipIisCustomErrors = true;

in your error page. After that, your Error messages should show without problem.