Whole site crashes after installing Gold Cart

I bought Gold Cart primarily for different view styles but when I install the whole site goes white back and front end. When I delete the plugin it comes back. Not sure what is going on. I have modified some files in WP ecommerce to accomodate eShipper I wonder if that is the issue…

Any ideas would be helpful.

https://www.ads-software.com/plugins/wp-e-commerce/