For developers: Use custom application status pages

You can customize the application status pages by directly modifying the HTML pages that are located in the AppData folder or by overriding the SitefinityHttpModule methods programatically.

Sitefinity CMS creates HTML pages under the AppData folder of your application, which are reused during later system startup or upgrade phases. If such pages exist, the system reuses them. If no such pages are present, system creates them using default markup embedded in Sitefinity CMS. In case you want a different design, you can modify these pages.
For more information, see Types of application status pages » Status page location.

You could implement custom pages during the restart and upgrade phases of Sitefinity CMS by overriding the following SitefinityHttpModule methods:

• OnSystemRestarting(HttpContext context, string html = null, string scriptUrl = null)
  This method is called on the initial request during system restart. Because the system is not able to handle the request at this time, this method completes the request and sends The system is initializing/restarting... message.
• OnSystemUpgrading(HttpContext context, string html = null, string scriptUrl = null)
  This method is called on the initial request during system upgrade. The request should be completed here, because the system is not able to handle the request at this time, this method completes the request and sends The system is upgrading... message.

To customize the application status pages, perform the following:

1. Open your project in Visual Studio.
2. In the context menu of SitefinityWebApp, click Add » Class...
   This way, you add add a custom Http Module class that derives from SitefinityHttpModule.
3. Override the OnSystemRestarting and OnSystemUpgrading methods by pasting the following code inside the newly created class:
4. Register your new module in your web.config.
   Perform the following: