Problem: The client's site lost its layout and design after uploading a backup. Solution: We recommend checking the restoration process of the site, as the layout information is typically stored in the database. It's possible that the issue stems from how the site was restored. For a smoother migration process, we suggest using plugins like Duplicator or All-in-One WP Migration.
If this solution does not resolve your issue, or if it seems outdated or irrelevant to your case, please do not hesitate to open a new support ticket. We also highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent fix, and confirming that you have installed the latest versions of themes and plugins.