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Internet Solutions


Authorization failed by ISAPI/CGI application


The web server has denied the login request. The web server allows extensions to be added to the server that are written by other developers or a CGI type application (another langauge). This extra code has rejected the login, likley due to the server having the wrong file or directory permissions.

Server Error

401.5 - Unauthorized: Authorization failed by an ISAPI/CGI application.

The URL you attempted to reach has an ISAPI or CGI application installed that verifies user credentials before proceeding. This application cannot verify your credentials.

Error messages will differ depending on the web server and if replaced by the web site designers.
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Frequency is relative to other Internet warnings and errors.
  Solutions and Fixes  

This issue can only be fixed by the web site owner.

Notify Webmaster
    Add    Flag
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You might notify the webmaster about the issue. Include the error number and the address (URL) where the error occurred along with any other relevant details.

Many sites use an email address in the form where you replace with the web sites address (don't include a www). Keep in mind with the amount of spam, they may use a different address and/or it might get ignored. Check the websites' contact information to get reliable contact information.

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  FaultWire Staff
Posted: 8-Oct-2008
  Official Explanation  
  technical details

Authorization failed by ISAPI/CGI application. An ISAPI application or a Common Gateway Interface (CGI) application does not let the request be processed because of an authorization problem.

(From Microsoft - The HTTP status codes in IIS 7.0)

Additional notes for the web server administrator - Microsoft Knowledgebase articles 942078, 906474.
  Forum Help  
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Check out what others say about this issue and review or add your own comments and solutions!

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  Research this Issue  
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"401.5 Authorization failed by ISAPI/CGI application" is only supported by Microsoft IIS (Internet Information Services) web servers.

ISAPI = Internet Server Application Program Interface

The four hundred series of errors indicate something was sent to the remote web server incorrectly.

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