ASP.NET MVC 403 Error

There is an error, when using ASP.NET MVC, that gives you HTTP 403 error.

When, the rest of the MVC site is working, but it cannot access a specific controller, look for a folder named after the controller.

For instance,

If the controller that cannot be accessed is SecurityController, but the rest of the controllers work, look for a folder in the root directory named "Security". ASP.NET MVC tries to access this folder instead of the actual controller.