HTTP Error 404.3-Not Found in IIS 10

Question

I use IIS version 10 and Windows 10 and VisualStudio 2015.

After I add WEB application to IIS site and open it I get error:

HTTP Error 404.3 - Not Found

The page you are requesting cannot be served because of the extension configuration. If the page is a script, add a handler. If the file should be downloaded, add a MIME map.

I installed IIS sub components from:

Control Panel -> Programs and Features -> Turn Windows features on or off

As described in this post by Mekanik.

Here is screenshot of installed sub components:

But it didn't helped me and still I get the same error.

Any Idea why I keep getting this error above maybe it has something to do with version of IIS 10?

Answer 1

I understand that this is an old issue but in case anyone else comes across it:

It is related to Handler mapping, you need the svc-integrated mapping for the site in question:

Handler mapping in question

In order to make sure this mapping appears you need to go to control panel -> turn windows features on or off -> .NET Framework 4.7 Advanced Services (or equiv .net ver) -> WCF Services -> HTTP Activation

Turn on Http Activation and refresh IIS. This should add the mapping and fix the error.

Http Activation Feature Location

Answer 2

I had the same problem for a WCF web service. Fixed it as follows: Open - Turn Windows Features ON or OFF, then Enable HTTP Activation

Answer 3

What kind of application are you browsing ? Based on the extension make sure you have proper handler mapping i.e. IIS Manager => Sites => specific site => Handler mappings

Another thing is in IIS Manager Select the Server (above Application Pools) double click on ISAPI and CGI Restrictions and see if everything is allowed there.