2261: W3 message read raw not supported
The IIS Internet Server Application Programming Interface (ISAPI) extensions and filters can extend and modify the request-processing capabilities of IIS. ISAPI applications are run in isolation to enhance server stability.
Event 2261 is generated when an attempt was made to load a particular filter, but it requires the SF_NOTIFY_READ_RAW_DATA filter notification and this notification is not supported in this IIS version.
How could you resolve this situation?
IIS 7.0 does not support the SF_NOTIFY_READ_RAW_DATA notification for ISAPI filters. If you have to use an ISAPI Filter that requires this notification, you must run the filter on IIS 6.0 in IIS 5.0 isolation mode.