- 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".
- Disable non-native modules. It is recommended to choose "Yes" for this option, as some module might prove a hindrance when upgrading PrestaShop.
- Upgrade the "default" 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.
- Upgrade the default e-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.
- Step-by-step mode. PrestaShop 1.5 Dev mode only. If enabled, the module will stop at each step to ask you for confirmation.
- Display PHP errors. PrestaShop 1.5 Dev mode only. If enabled, the module will displays PHP errors, which could help you discover server issues that would otherwise stay hidden from view.