HTTP Error 401.4 – Authorization failed by filter
Description of HRESULT # The operation completed successfully.
- Find out which ISAPI filter causes the problem. To do this, follow these steps to access the Failed Request Event Buffer (FREB) XML file of the Web site that generates the 401.4 error message:
- Locate the FREB XML file for the request that you made to the server. The FREB XML file is typically located in the following folder:drive:\inetpub\logs\FailedReqLogFiles
- Use Windows Internet Explorer to open the FREB XML file. Typically, the name of the FREB XML file resembles the following: frXXXXXX.xmlNote The XXXXXX placeholder represents the FREB ID.
- In the FREB XML file, click the Request Details tab, and then expand the FILTER_START node. You can now see the physical path of the ISAPI filter that causes the problem.
- Locate the FREB XML file for the request that you made to the server. The FREB XML file is typically located in the following folder:
- Contact the developer of this ISAPI filter to obtain the resolution.