I recently downgraded to woocommerce 2.0.20 after discovering my theme was not compatible with the 2.1 update. After restoring the pages that the update moved to trash everything is working properly besides my thanks/order received page. After the order is placed it redirects to /order-received and shows "Thank you. Your order has been received." but with no order data. Editing the final line of code in themes>woocommerce>checkout>thankyou.php shows changes such as <p> to <h2> which is telling me that it is calling only the final, if all else fails, line of code and is skipping the entire function. I have no idea as to why.
Here's the link http://aqualifeaquarium.com/shop/
Let me know if you need anything else, I'm new here. And thanks in advance!