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.

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.

Here's a screenshot of the error page: 

Solution:


Use aspnet_regiis.exe to register version of .NET framework you are using.

This is a comon issue and happens when IIS is installed after VS or .NET framework.

  

Version of .NET Framework	Location of Aspnet_regiis.exe file
.NET Framework version 1	%windir%\.NET\Framework\v1.0.3705
.NET Framework version 1.1	%windir%\Microsoft.NET\Framework\v1.1.4322
.NET Framework version 2.0, version 3.0, and version 3.5 (32-bit systems)	%windir%\Microsoft.NET\Framework\v2.0.50727
.NET Framework version 2.0, version 3.0, and version 3.5 (64-bit systems)	%windir%\Microsoft.NET\Framework64\v2.0.50727

Eg:

1. Run the command prompt (cmd)

2.Navigate to C:\Windows\Microsoft.NET\Framework\v2.0.50727

3.Run this command aspnet_regiis.exe –i