This error occurs when a CGI application like Cart32 is unable to provide all of the necessary headers for an HTTP request/response. There are 2 major reasons this happens: speed and misconfiguration. Below are the two explained in more detail.
CGI applications often times will simply execute, then dispose of themselves. However, in an environment where multiple requests are coming in every second you may find this error popping up. The solution, in the case of Cart32, is to make sure caching of ISAPI extensions is turned on. This is done in IIS. You can follow these steps to verify this setting:
- Open IIS
- Right click the site where Cart32 is installed and choose Properties.
- Change to the Home Directory tab.
- Click on the Configuration button (which will open another window).
- On the Mappings tab, mark the checkbox for Cache ISAPI Extensions.
- Click OK on both open windows and then restart IIS. (If you cannot restart IIS for some reason, on WS2003 you can simply stop/start the application pool that the site runs under)
Mis-configured Data Execution Prevention
The other reason this error can occur is due to Data Execution Prevention (introduced in WS2003 and newer) being mis-configured. Please refer to this article for more information on how to properly configure DEP for Cart32.