IIS Error Message – “The specified CGI application misbehaved by not returning a complete set of HTTP headers”
A user of one of my web applications reported that he was getting the error “The specified CGI application misbehaved by not returning a complete set of HTTP headers” after logging in.
After spending several hours Googling for answers I logged in and went to work with the intent of trying each of the few dozen or so possible solutions. Luck was on my side and the first thing I tried worked.
The cause was part of the script that was running the ImageMagick convert command to get the version information. By default my application uses a Linux path (/usr/bin/convert) because that’s what most web servers are. But that line was triggering the error on IIS. So I changed the code to not run those lines and the program works without a problem.