We used to have a list of products with different variations and prices. Now of a sudden the variations disappeared on the product, even though it used to be there. As a result there’s no option of customer to select anymore.
Product variations cannot disappear without a reason, it’s not something that happens in CS-Cart. Have you taken any unusual action recently? Upgrading your store, upgrading add-ons, moving to the different server, tampering with the database?