ERROR:
HTTP Error 500.2* – Internal Server Error
An ASP.NET setting has been detected that does not apply in Integrated managed pipeline mode.
CAUSE:
IIS7 and above default to using “integrated pipeline mode”; whereas, IIS6 and below utilize what is now deemed “classic mode.” In classic mode, IIS uses ISAPI extensions; whereas, integrated mode handles all requests through a pipeline of IIS and is integrated with SP.NET through this same pipeline. Integrated mode is much more efficient with ASP.NET. Read more about how to enhance your application with integrated pipelines here.
RESOLUTIONS:
There are multiple resolutions to this problem; however, depending on your application, the quickest way to resolve this problem can be to:
1. Open IIS
2. Navigate to the app pool for your application
3. Switch from “integrated mode” to “classic mode.”
Other possible options:
1. If your application is running legacy code, then update your code.
2. If you are running in 64-bit Windows then navigate to “Advanced Settings” and set “Enable 32-Bit Applications” = True.
3. Try keeping your default website in the default app pool, ie Integrated Pipeline mode, but keep your virtual directory in classic mode.
4. This last option is debatable and may only be considered as a temporary fix. In your web.config, insert the following:
<configuration>
<system.webServer>
<validation validateIntegratedModeConfiguration="false" />
</system.webServer>
</configuration>