Merge pull request #1848 from M0rgan01/add_upgrade_checklist_v9

Add post-update-checklist part (v9)

basics/keeping-up-to-date/upgrade-module/post-update-checklist.md

@@ -0,0 +1,28 @@
+---
+title: Post-update checklist
+weight: 50
+aliases:
+  - /9/development/upgrade-module/post-update-checklist
+---
+
+# Post-update checklist
+
+Below is a list of actions that should be done following a PrestaShop update.
+
+## Main steps
+
+The following steps will be executed during the upgrade:
+
+- **Refresh the page.** You’ll need to sign in to your back office again.
+- **Re-enable and check your modules** one by one.
+- **Make sure your store’s front office is working properly:** try to create an account, place an order, to add a product, etc.
+- **Disable the maintenance** mode in General settings > Maintenance.
+
+## Troubleshooting
+
+- If some images don’t appear in the front office, try regenerating thumbnails in Preferences > Images. You should check the images of products, categories…
+- If something’s wrong, you can restore a backup with this module. Your backup is available at {admin}/autoupgrade/backup and can be restored either manually or via the [command line interface][1]
+- If you can't access your back office, try enabling the debug mode manually in config/defines.inc.php by setting _PS_MODE_DEV_ to true ([see the dedicated documentation][2])
+
+[1]: {{< relref "/9/basics/keeping-up-to-date/upgrade-module/upgrade-cli" >}}
+[2]: {{< relref "/9/development/configuration/configuring-prestashop#enabling-debug-mode" >}}