Event ID 2261 — IIS ISAPI Functionality

  • Article

Applies To: Windows Server 2008 R2

Internet Information Services (IIS) ISAPI (Internet Server Application Programming Interface) extensions and filters can extend and modify the request-processing capabilities of IIS. ISAPI filters require a long time to be written, offer no native support for session handling, and can be cumbersome to maintain. IIS 6.0 and IIS 7.0 run ISAPI applications in isolation to enhance server stability. While ISAPI filters can still be used in IIS 7.0, it is easier for developers to add managed or native modules that integrate into IIS 7.0’s new modular architecture.

Event Details

Product: Internet Information Services
ID: 2261
Source: Microsoft-Windows-IIS-WMSVC
Version: 7.5
Symbolic Name: W3_MSG_READ_RAW_NOT_SUPPORTED
Message: An attempt was made to load filter '%1' but it requires the SF_NOTIFY_READ_RAW_DATA filter notification and this notification is not supported in this IIS version.

Resolve

SF_NOTIFY_READ_RAW_DATA not supported on IIS 7.0

IIS 7.0 and IIS 7.5 no longer 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 (however, notice that this is not a recommended practice). For more information, see the article Information about ISAPI filters that register the SF_NOTIFY_READ_RAW_DATA event in Internet Information Services version 6.0.

Verify

You can use IIS Manager to verify that an ISAPI filter is functional by using one of the following methods:

  • Performing a test browse on the Web site or application that uses the ISAPI filter.
  • Verifying that a worker process is running for the Web site or application that uses the ISAPI filter.

Note:  An IIS worker process does not exist until a request is made to the application pool for the Web site or application. For this reason, you may have to test browse the Web site or application before you can verify that a worker process is functional.

To perform these procedures, you must have membership in Administrators, or you must have been delegated the appropriate authority.

Perform a test browse on the Web site or application that is using the ISAPI filter

To perform a test browse by using IIS Manager:

  1. Click Start, click Control Panel, and then click Administrative Tools.
  2. Right-click Internet Information Services (IIS) Manager and select Run as administrator.
  3. In the Connections pane, expand the computer name.
  4. Expand Sites.
  5. Select the Web site or application that is using the ISAPI filter that you want to verify.
  6. In the Actions pane, click the link under Browse. If the Web page appears, the ISAPI filter is functional.

Verify that an application pool worker process is running for a Web site or application

To verify that an application pool worker process is running:

  1. Click Start, click Control Panel, and then click Administrative Tools.
  2. Right-click Internet Information Services (IIS) Manager and select Run as administrator.
  3. In the Connections pane, select the computer name.
  4. In Features View, under the Feature Name column heading, double-click the Worker Processes management feature. A list of currently active application pools and worker processes will appear.
  5. Examine the application pool corresponding to the Web site or application that uses the ISAPI filter. The State column for the worker process will indicate Running if the worker process is running.

IIS ISAPI Functionality

Internet Information Services (IIS) 7.5