Sitecore might fail to start in ASP.NET 4 Classic application pool mode


Description

Note: This known issue was fixed in CMS 6.5 rev. 110419 (Technical Preview) for the setup.exe. This known issue still applies when you install Sitecore from the ZIP file.

Sitecore might fail to start with the following errors when you run the application in an ASP.NET 4.0 application pool using Classic pipeline mode.

The page you are requesting cannot be served because of the ISAPI and CGI Restriction list settings on the Web server.

 

The requested content appears to be script and will not be served by the static file handler.


This happens if the IIS configuration does not allow the .NET 4 aspnet_isapi.dll extension to execute.

Solution

  1. Open the IIS Manager and open the "ISAPI and CGI restrictions" feature. You will see one or two extensions with the name "ASP.NET v4.0.30319" which are set to "Not Allowed".
  2. Select the extension and allow it.
  3. Sitecore should now start correctly.
  4. If the error is still there, select the website in the left pane of the IIS manager, double click Handler Mappings section, then select 'Revert to parent' in the Actions pane, and confirm your selection by pressing 'Yes' in the prompt dialog.