Recently tried to get a new MVC 4 application running on IIS7 and ran into an issue that required a hotfix. The IIS7 server was 2008 SP2 fully patched and had both .NET 2.0 and .NET 4.5 installed, however, whenever I attempted to load the application, IIS would return a 403.14 error message about a directory listing being denied.
Many solutions suggested that ASP.NET wasn’t registered properly, and I confirmed that my application pool settings were correct (need to run Integrated Mode or configure asp.net to handle all traffic so requests are routed to the controllers). Others recommended code solutions, but Sean Anderson’s solution on this stackoverflow.com post was the resolution for me.
There’s an extensionless URL hotfix (I blogged about this hotfix in relation to 404 errors) for IIS7 that is required: http://support.microsoft.com/kb/980368.
ASP.NET Routing is a powerful feature introduced in .NET 3.5 SP1 and included with .NET 4.0 that allows a developer to route URL’s that are not real files. There are several ways you can accomplish this same task, but having it in the ASP.NET pipeline allows the developer great flexibility in how URL’s are routed. However, it does not always work “out-of-the-box” for devs. The most common error I’ve seen is a 404 error – meaning the page cannot be found.
There can be several contributing factors. If you are attempting to utilize extenionless URL’s, ensure you have the appropriate IIS hotfix installed: http://support.microsoft.com/kb/980368. More commonly however, the issue is a result of the module not firing for your request type. The easy fix is to add runAllManagedModulesForAllRequests=”true” to the modules tag in your web.config. However, that could have performance implications as you are now telling IIS to ignore the preCondition setting for all modules. The alternative solution is to remove the managedHandler preCondition for the URLRouting module: