This article applies to any CGI program running on Microsoft IIS.

Last Updated: 23 May 2002

Problem

When you run a CGI program, the server says the application "misbehaved," and that there were either missing or incomplete headers.

Details

If you get an error about missing or incomplete headers, then you probably haven't given sufficient file permissions to the system DLLs (in C:\WINNT35\SYSTEM32 or C:\WINNT\SYSTEM32, usually). This error message is especially frustrating, since it tells you that the CGI program misbehaved, where in fact it is the server's problem. If for any reason the server cannot launch the CGI program, then the CGI program won't run. If the program doesn't run, it won't produce any output. If it doesn't produce any output, IIS tells you that the CGI program misbehaved. An error message saying WHY the server couldn't run the CGI would be much more informative.

Solution

Give the IUSR_<machinename> account Read permissions to the system DLLs, and Change permissions in the temp directory. Enable security auditing and check for access denied messages if the problem persists.