You have a major computer problem if the script makes your computer shut off. I couldn't say if it's a corrupt Photoshop installation or a hardware issue, but that's majorly bad juju, and the script author is unlikely to be able to help you.
Describe what lighting you're using to light the Color Checker; I'd recommend direct sun daylight if possible to ensure the entire Color Checker is lit evenly. If it's not lit evenly, or over- or under-exposed, the results will be skewed to the point where the script may not be able to calculate a usable result. Can you post your RAW online and then post a link to it so I can see it?