This error indicates that your application is not coded to run in Integrated Pipeline Mode.
To resolve this issue you must either:
Update your code to run in Integrated Pipeline Mode.
Or log into your Control Panel and go to your Site Info Manager and change the pipeline mode from Integrated to Classic.
See our Knowledge Base article on Application Pool Pipeline Mode in IIS 7
Please note: Whenever possible, we recommend updating your web application to run in Integrated Pipeline Mode. Running in Classic mode will prevent your web application from taking advantage of the enhancements that are only available in Integrated Pipeline Mode.
Article ID: 798, Created On: 4/9/2010, Modified: 4/21/2011