- Preserve the original theme. The upgrade process overwrites the default theme with its latest incarnation. If you have made changes to the theme directly, you can protect these changes by choosing "Yes". As a reminder, it is NOT recommended to edit the default theme! You should make a copy of the theme, and make changes to that copy.
- Keep default mails. An update might bring new default e-mail templates. By default, the upgrade will replace the existing ones with the ones from the newer archive, and add the new templates. If you have customized your templates, it is recommended you keep them. You would then have to customize the new templates in order to fit the general style of your shop.
- Deactivate custom modules. It is recommended to choose "Yes" for this option, as some module might prove a hindrance when upgrading PrestaShop.
- Manual mode. If enabled, the module will stop at each step to ask you for confirmation.
- Server performance. Some shared hosted offer poor performance, which might hinder the performance of the upgrade process, or even make it fail. "Low" is thus selected by default, but if you know you have a powerful server, you can choose "Medium" or even "High".
The Upgrade process
Once all the indicators are green, the update button appears in the "Upgrade" section, along with an indication of which Smarty version you are currently using, and the URL from which the new version will be downloaded.
Click Clicking the "Upgrade PrestaShop now !" triggers the whole process.
Once the upgrade process is launched, the whole configuration page is replaced by two sections: "Activity Log" and "Rollback".
Once you have made sure your PrestaShop installation is up and running, you can re-enable your shop using the option in the "Maintenance" page of the "Preferences" menu, then make tests on your front-office: browse products, sort them, try to order one, etc. In short, go through the entire buying process in order to make sure that you won't miss a sale.
PrestaShop's own backup files are saved on your server, and if it turns out your update has gone badly, you can find them in the "Rollback" section of the "Upgrade" sub-tabconfiguration page for the 1-Click Upgrade module.
Backup files are created as soon as the upgrade process is started, and are available immediately in the "Choose your backup" drop-down list.