500 Internal server error means that there is some Fatal error in PHP script or on the server side. You can turn on debug mode in WordPress to see the error https://codex.wordpress.org/Debugging_in_WordPress
If it will not show any errors then contact your hosting provider and ask them to give you a server error log to check what is wrong.
I’ve checked your site and do not see the problem. Please explain your issues in detail.
Also, note that the latest theme version is 3.3, so to good work with the latest version of woocommerce you need to have 3.3 v of the theme.