If you updated Woocommerce to version 2.3 you have to update the Theme to the latest version. This is an absolute must and Theme and Woocommerce will not function properly if you do not update the Theme!
Theme is WooCommerce 2.3. ready.
You need to set images for single product page becaouse from now one we use default WooCommerce images display for single product view.
Go to WooCommerce->Settings->Product->Display and set images size to:
After you save this setings install plugin Regenerate Thumbs and run it.