This error can occur when the InstallScript engine is not installed on the computer, or if the latest script needs to be downloaded. As a fix to this error message, you can download and install the latest InstallShield Script engine (although IDL 6.3 is a very old version and I am not sure if it will be compatible with the latest version of the InstallScript engine, but you can try it). Go to the FlexEra website and search for 'Update to the Latest InstallShield Installation Engines' in the Knowldge Base for more information. Hope this helps.