Like gellyfish, I'm confused by what a "CGI editor" might be, but I can have a guess at what your problem is.

Either your program isn't outputting the correct CGI headers (you need to, at least, print a Content-type header - use the header method from CGI.pm) or there is an error in your program and it's outputting an error message before it gets to output the headers. In this case, the real error will almost certainly be in your web server error log.

Also see Suffering from Buffering.