The Amber Sea online store worked on the CS-Cart platform version 4.8. Our client decided to update the look of the site. With the page layouts, he approached a contractor who redesigned them through the platform’s core files. This is unacceptable for CS-Cart: controllers, functions, templates, database structure and other elements are recommended to be modified only by using add-ons. Making changes to the core files can lead to conflicts in future updates. Exactly that happened later: while updating the store to version 4.9. the page layout crashed, the theme templates stopped working, the appearance of the online store was severely damaged.