The first time I was told of an issue was whan Adding to Cart stopped adding to cart and that the Checkout page went blank. I diabled ajax and Add to Cart works again but Basket shipping (select a new shipping method) loads the wholw website into the basket and then crashes. If you made it to the checkout page then this simply crashes.
The problem does not seem to exist when logged in!
I disabled all plugins and no change
I changed to 2012 theme and all is well.
Does this mean it's a theme issue?
The live broken site is https://www.creightonscakes.co.uk
Gratefull for a steer please?