Getting 404 error on MVC web-site

Question

I have an IIS7.5 web-site, on Windows Server 2008, with an ASP.NET MVC2 web-site deployed to it. The website was built in Visual Studio 2008, targeting .NET 3.5, and IIS 5.1 has been successfully configured to run it as well, for local testing.

However, whenever I try and navigate to a page running in IIS7, I get a 404 error.

I have checked the following things:

• There is no corresponding 404 log entry in IIS logs.
  • Actually, there are 404 entries in the IIS log.
• The application pool for the web-site is set to use the Integrated pipeline.
• The "customErrors" mode is set to off.
• .NET 3.5 SP1 is installed
• ASP.NET MVC 2 is installed
• I've used MVC Diagnostics to confirm all MVC DLLs are being found.
• ASP.NET is enabled in IIS, which we've demonstrated by running the MVC Diagnostics page.
• KB 2023146 did highlight that HTTP Redirection was off, so we've turned it on, but no joy.

EDIT Ok, so we've installed the world's simplest MVC application (the one which is created when you create a new MVC2 project in Visual Studio), and we are still getting 404s on any page we try and access - e.g. <my_server>/Home/About will generate a 404.

Any ideas will be greatly appreciated!

Answer 1

We finally nailed this issue by exporting the IIS configuration of a working server, and comparing it to ours.

It was a really obscure setting which had been changed from the default.

IIS ROOT → request Filtering → Filename Extensions Tab → Edit Feature Settings → Allow unlisted file name extensions

This should be ticked.

This can be set at the IIS level, or the site-level.