If you changed any files of your CS-Cart installation, you’ll see them on the list of local modifications when you install an upgrade. The Upgrade Center will back up those files, so that you can resolve the conflicts manually after the upgrade. To do it, follow these steps:
To look through these files, find them in the backup archive in the var/backups directory of your CS-Cart installation and compare with the original files. If there are some modifications in code which you would like to keep, apply them to the files once again.