I have a WooCommerce 'store' for my farm using the Mystile theme. Product images worked beautifully until approximately sometime in the last week. The popup (larger) images that should appear when you click on the thumbnails in the gallery on the individual product page won't appear. The screen dims as normal, but you can't see the image unless you zoom out on your browser - sometimes as far as 50%.
For an example, check http://snowdenfamilyfarm.com/herds/dairy-goats/cada/