ASP.NET MVC 3 Windows Authentication problem - redirects to Account/Login

ASP.NET MVC 3 has its quirkiness here and there. Sometimes it’s a lack of support for something, and other times it’s downright buggy.

An issue I came across recently, is something to do with Windows Authentication. There’s a lot of resource on the web on how to run ASP.NET MVC with Windows Authentication. There’s even a project template, the Intranet site, which ships with MVC 3. It should be a no-brainer!

The issue I came across, prevented ASP.NET from using Windows Authentication. Even though I had set authentication mode to Windows in Web.config:

And disabled anonymous authentication on the website in IIS – it always redirected all requests to /Account/Login, as if it was using some sort of default Forms Authentication.

This coursed a server error – the dreaded Yellow Screen of Death, since I didn’t have a login form on my site, I had no controller/action for Account/Login.

Known issue

After searching the web for a while, I came across the release notes on the ASP.NET MVC website. At the bottom, there’s a section called ‘Known issues‘, and one of the last issues reads:

There’s a known issue that causes Forms Authentication to always redirect unauthenticated users to ~/Account/Login, ignoring the forms authentication setting used in Web.config. The workaround is to add the following app setting.

And much to my disappointment, this didn’t do the trick! Long story short, it turned out that I needed another setting as well, as pointed out in the comment of this Stackoverflow question: