You receive a "The specified CGI application misbehaved" error message


When you use a Common Gateway Interface (CGI) application with Microsoft Internet Information Server (IIS), the following error message appears:

CGI Error:
The specified CGI application misbehaved by not returning a complete set of HTTP headers. The headers it did return are:


This error is caused by the return of an incomplete or incorrect set of headers by the CGI application. The CGI application may be written incorrectly. As well, logic errors, API failures, or anything that causes the CGI application malfunction can also cause this error.


Modify the source code for the CGI application header output. The following is an example of a correct header:

   print "HTTP/1.0 200 OK\n";
print "Content-Type: text/html\n\n\n";

If the CGI is written in C++, it is possible to debug the application and ascertain the problem. Instructions can be found in following article:

238788 How to debug CGI applications running under IIS