WordPress 5.9

WordPress 5.9 substantially expanded block-based site building beyond post and page content. It introduced the Site Editor for block themes, allowing administrators to edit site-wide templates and template parts such as headers and footers from the editor. The release added the default Twenty Twenty-Two block theme, expanded Global Styles and theme.json controls, and introduced or matured blocks for navigation, querying and displaying posts, comments, and reusable layout patterns. It also improved the block editor with better typography, layout, gallery, and list-view controls. These capabilities changed how themes can be built and customized: a block theme can define templates and design settings as blocks and configuration rather than relying solely on classic PHP template files and Customizer settings. WooCommerce is a plugin that runs on WordPress, so a WooCommerce store is a WordPress site and its WordPress version matters to it just as much as its WooCommerce version does.

WordPress 5.9 has reached end of life, so it should not be treated as a maintained platform baseline. Remaining on it increases exposure to unremediated issues in the WordPress core line and leaves the site dependent on older editor, theme, and plugin interfaces. Plugin and theme vendors commonly move their testing and compatibility commitments forward, which can make upgrades to extensions, WooCommerce, PHP, or hosting infrastructure harder to validate while the site remains on this old core version. Sites using block themes or early full-site-editing configurations face an additional compatibility risk because the Site Editor, Global Styles, theme.json schema, and individual blocks have continued to evolve. A direct upgrade without testing can therefore alter template output, style presets, navigation behavior, block markup, or editor controls. For WooCommerce stores, an unsupported WordPress core version can constrain the versions of WooCommerce and payment, shipping, tax, and security extensions that can be safely used.

Plan an upgrade to a currently supported WordPress release rather than treating 5.9 as a long-term target. First, take verified backups of files, the database, uploads, and any deployment configuration, and confirm that restoration works in a non-production environment. Inventory the active theme, child theme, custom plugins, mu-plugins, WooCommerce extensions, integrations, and server-side PHP and database dependencies. Build a staging copy that matches production, update or replace extensions that do not support the intended WordPress and PHP versions, and review vendor compatibility notes before updating core. Test critical public pages, authentication, forms, scheduled jobs, caching, search, media handling, email delivery, and any external integrations. If the site uses WooCommerce, test the full customer path: product display, cart, checkout, payment authorization, order creation, taxes, shipping, transactional email, refunds, and webhooks. For block themes, explicitly compare site templates, template parts, navigation menus, Global Styles, reusable blocks or synced patterns, and custom theme.json settings before and after the upgrade. Deploy through the normal release process, retain a rollback plan, and monitor logs, checkout activity, and front-end rendering after deployment.