After upgrading the database to Odoo 17, the Website Builder theme no longer loads correctly — the website displays only plain HTML without styling because CSS assets are not being applied. The theme is still installed, but most CSS files are missing or returning 404/403 in the browser inspector, and the /web/assets/ bundles do not include the expected theme resources. I have already restarted the server, upgraded website modules, cleared asset and browser cache, rebuilt assets with --update=all, and verified that the theme is still active, but the problem persists. The issue did not exist before the upgrade, and now the entire layout looks broken and unstyled, affecting fonts, colors, sections, and spacing. This happens on all pages and makes the website unusable for visitors, so I’m trying to identify how to restore CSS/theme assets properly after the upgrade to Odoo 17.