Hello,
You need to update the theme to latest version that compatible with woocommerce version that you use.
https://www.8theme.com/demo/docs/classico/#theme_installation_and_upgrade
Before uploading theme files delete “woocommerce” folder, which is located in wp-content/themes/classico/ to avoid problems with old files.
You will lose only changes in theme files if you made them in parent theme files.
Don’t forget to create backup of your files and database before starting update process!
You need to enter your purchase code to activate the theme and skip Setup Wizard.
Also updated all plugins https://www.8theme.com/download-plugins/ (to update free plugins just click on update link from your Dashboard (Plugins > Installed Plugins), to update premium plugins, connect to your server using FTP. Copy extracted plugins folders into wp-content/plugins/ ).
Regards