I've read of people experiencing the same issue. Some blamed HTTPS, but I'm not using SSL. Others mentioned plugins, but the problem still occurs if I disable them. Others say the WooCommerce pages must be there and have the proper shortcodes on them, but in my case I've left everything as is and double checked.
While it's possible that what is causing the error could be in my theme and I will investigate further, I wonder if any of you had the same issue and how you solved it.
I'm using the latest stable version of WordPress and WooCommerce.