Nouveau correctif ISA Server 2004 : Users receive an :Error Code 502: Proxy error. The parameter is incorrect. (87)

Un nouveau correctif (bug) pour ISA Server 2004 corrigeant les problèmes liés à l’utilisation de signatures HTTP.


“After you configure Microsoft Internet Security and Acceleration (ISA) Server 2004 to filter HTTP content based on signatures or on extensions, users in your organization experience the following symptom.

When a user visits certain URLs, that user receives the following error message in the Web browser:

Error Code 502: Proxy error. The parameter is incorrect. (87)

If you remove all signatures and extensions from the HTTP Filter settings, and if you configure the HTTP Filter component to allow all signatures and extensions, you no longer experience this problem.


This problem occurs because of a problem in the ISA Server 2004 HTTP Security Filter component. This component is named HTTPFilter.dll.




A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next ISA Server 2004 service pack that contains this hotfix.


File information


The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

ISA Server 2004, Standard Edition
    Date         Time   Version       Size     File name
   31-Mar-2005  18:22  4.0.2163.251  120.320  HTTPFilter.dll

ISA Server 2004, Enterprise Edition
    Date         Time   Version       Size     File name
   03-Apr-2005  14:00  4.0.3440.251  128.792  HTTPFilter.dll
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