404.2 Error after installing .net 4.0

Question

I have a project which I have upgraded to .Net 4.0, but when I try to access it, I retrieve the following error:

HTTP Error 404.2 - Not Found
The page you requested could not be displayed because of the settings for the list of ISAPI and CGI restrictions on web server.
ErrorCode: 0x800704ec
Handler PageHandlerFactory-ISAPI-4.0_32bit

Do I need to do something extra to the IIS 7 or APP pool, when converting an existing site to a .NET 4.0 site?

Also if I look at ISAPI both 32bit and 64bit of the .Net 4.0 is installed.

Answer 1

In IIS, enable .NET 4.

Here is image:

Answer 2

I take it you're running on IIS6 right now..

Open the IIS manager, and go to the Web Service Extensions area.. You'll be able to enable .NET 4 in there.. All new extensions are disabled by default :)

If you're running on IIS7, .NET might not have registered in IIS.. Then open up an admin command prompt and navigate to the .NET 4 framework folder (C:\Windows\Microsoft.NET\Framework\v4.{version}). If you're on a 64 bit machine go to the Framework64 folder instead of the Framework folder. Then run aspnet_regiis -i in there

Answer 3

I had this same issue. Strangely, for me it would run in integrated mode but not in classic mode for .NET 4. After enabling the .NET 4 extensions via the Isapi and Cgi restrictions section in IIS 7, it then began working in both modes. The Isapi and Cgi restrictions section is located at the server level node in IIS manager. This option should not be confused with the Isapi Filters section at the site level.