WordPress 6.9 Known Issues in March 2026: What Broke, What’s Fixed, and What’s Still Open
WordPress 6.9 shipped December 2, 2025. It brought some genuinely good features — native collaboration, a new Abilities API, 7 new blocks, real performance gains. We covered those in a separate post.
But it also broke some things. And if you’re a site owner or developer who updated early without a staging environment, you may have found out the hard way.
This post is a running reference. We’re documenting every confirmed issue from 6.9, what caused it, whether it’s been fixed, and what to do if you’re still hitting it. We’ll update it as 7.0 (scheduled April 9, 2026) approaches.
Why Did 6.9 Break More Than Usual?
Before the list context matters here.
WordPress 6.9 made two foundational architectural changes that affected a wide range of plugins:
1. The Abilities API
WordPress replaced its scattered current_user_can() permission checks with a unified capability registry. Plugins that managed user roles, memberships, or security rules using the old pattern started throwing fatal errors or silently failing — because capabilities they were checking no longer existed in the expected way.
2. On-demand block style loading
Prior to 6.9, WordPress loaded CSS for every registered block on every page. 6.9 changed this to load only the styles for blocks actually present on the page. Better for performance — but it changed when and how stylesheets are enqueued. Any plugin or theme that was enqueueing styles at the wrong point in the page generation cycle started serving broken or unstyled pages.
These weren’t bugs in 6.9 itself — they were the intended changes. But they broke a lot of code that had been working for years. The good news: most of the major issues have been patched. The bad news: if you’re running outdated plugins or a classic theme that hasn’t been updated, you may still be hitting them.
The Issues, One by One
1. WooCommerce Checkout Errors
Status: Fixed — update to WooCommerce 10.4.2 or higher
This was the highest-severity issue from the 6.9 launch. WooCommerce 10.2 had serious problems under WordPress 6.9: carts displayed incorrectly, the “Place Order” button stopped responding on some setups, AMP pages conflicted, and refunded orders were mishandled in edge cases.
Automattic pushed a patch — WooCommerce 10.2.1 — the same day WordPress 6.9 went live. But even that was a temporary fix. The stable compatibility version that fully resolves 6.9 issues is 10.4.2 or higher.
What to do: Check your WooCommerce version in the plugin list. If you’re below 10.4.2, update immediately — and test checkout on a staging environment before pushing to production. If you’re running a modified checkout flow, test every step: cart, checkout page, order confirmation, and refund handling.
2. Yoast SEO Meta Box Missing in Block Editor
Status: Fixed — update to Yoast SEO 26.6 or higher
Yoast’s SEO panel failed to load properly in the 6.9 block editor. The meta box was either missing entirely or not syncing correctly with Elementor’s sidebar — which meant editors couldn’t set meta titles, descriptions, or focus keywords from the post editor.
The root cause was a combination of the block editor changes and the Abilities API shift. Yoast relied on legacy integration patterns that 6.9 changed.
What to do: Update to Yoast SEO 26.6+. If you’re running Yoast alongside Elementor, test that the SEO sidebar appears correctly in both the WordPress block editor and Elementor’s full-screen mode after updating.
If you’re on Rank Math or SEOPress instead of Yoast, check their changelogs for 6.9 compatibility — both have released updates addressing similar integration issues.
3. Elementor Visual Conflicts
Status: Fixed — update to Elementor 3.24 or higher
Elementor builds its own editing environment on top of WordPress. When WordPress 6.9 changed how the Interactivity API works — specifically how blocks communicate state with each other — Elementor’s custom editor couldn’t keep pace.
The result: layout rendering issues in the editor, blocks not loading correctly in preview, and in some cases broken widget saves. The most common symptom was the editor loading but not rendering the canvas.
What to do: Update to Elementor 3.24+. If you’re running Elementor Pro alongside Elementor Free, update both — the Pro plugin has its own compatibility release that needs to match.
4. Classic Theme CSS Breakage
Status: Partially fixed via 6.9.1 — may require a workaround for older themes
This one hit a lot of sites that had been running fine for years. The on-demand block style loading change in 6.9 affected classic (non-block) themes in a specific way: sidebars collapsed under content, grid layouts fell into single columns, and some themes lost container sizing entirely — causing posts to stretch to full viewport width.
The problem was that themes loading CSS in the classic way had their stylesheets loading in a different order than before, which meant block styles were overriding theme styles in ways that didn’t happen in 6.8.
The 6.9.1 maintenance release (shipped February 3, 2026) addressed some of these cases. But for heavily customized classic themes or child themes with deep CSS dependencies, you may still be hitting it.
Emergency workaround: Add this to your theme’s functions.php:
add_filter( 'should_load_separate_core_block_assets', '__return_false', 100 );
This disables the new on-demand loading system and restores the 6.8 behavior. It’s not a permanent fix — it trades the performance gains for stability — but it will stop the visual breakage while you work on a proper solution.
Longer-term fix: If your theme is from a reputable developer, check for a 6.9-compatible update. If it’s a custom theme, a developer needs to review the CSS enqueue order and update it to load correctly under the new system.
5. Abilities API Breaking Membership and Role Plugins
Status: Varies by plugin — check individual changelogs
Plugins that manage user roles, membership access, content restrictions, or security rules were hit hard by the Abilities API change. The old pattern of checking capabilities directly often produced fatal errors or silent failures when capabilities had been reorganized under the new system.
Notable plugins affected include various membership systems, user role editors, and security plugins that hook into capability checks. Symptoms ranged from members losing access to gated content, to white screens on role-restricted pages, to admin users being locked out of specific settings panels.
What to do: If you run any membership, user registration, or role management plugin, check its changelog for a “WordPress 6.9 compatibility” update. MemberPress, Restrict Content Pro, Members, and similar tools have all released compatibility patches. If yours hasn’t, contact the developer directly — or flag us and we can assess your specific setup.
6. Emails Failing to Send
Status: Fixed in WordPress 6.9.1
A bug introduced in 6.9 caused email delivery failures on some server configurations — including order confirmation emails, password resets, and contact form notifications. Not universal, but reports were widespread enough that it made the 6.9.1 fix list.
What to do: Update to WordPress 6.9.1 (released February 3, 2026). If you’re still on 6.9.0 and emails are failing, that’s your likely cause. After updating, send a test email from Settings → General and verify delivery.
If you’re on 6.9.1 and still experiencing email failures, the issue is likely separate — usually a misconfigured mail server or missing SMTP setup. That’s a hosting configuration issue, not a WordPress core issue.
7. Adjacent Post Navigation Infinite Loop
Status: Fixed in WordPress 6.9.1
A specific bug in how WordPress 6.9 handled Adjacent Post Navigation (the previous/next post links) caused infinite loops under certain query conditions. Most sites never hit this — it required a specific combination of query arguments — but when it did occur, it caused pages to time out completely.
What to do: Update to WordPress 6.9.1. Nothing else required.
8. Classic Theme Editor Styles Not Loading in Site Editor Preview
Status: Open — still being tested as of March 2026
This one is still active. When the Gutenberg plugin (version 22.5.3) is active alongside WordPress 6.9.1, classic theme editor styles added via add_editor_style() are not loading correctly in the Site Editor’s “Styles” view, or in Template and Pattern preview iframes.
This affects developers who use classic theme editor styles for consistency between the frontend and editor appearance. The styles render correctly on the frontend — the issue is the preview only.
Ticket: #75779 on the WordPress core Trac. The WordPress test team is actively working this one.
What to do for now: If you need accurate style previews in the Site Editor, either temporarily deactivate the Gutenberg plugin (and rely on core block editor only) or accept that previews may not match the frontend exactly until this is patched. Watch the ticket for a fix.
9. Navigation Overlay Back Arrow Not Closing Sub-Menus on Mobile
Status: Open — still being tested as of March 2026
On mobile devices, the back arrow in Navigation Overlay blocks isn’t closing sub-menus as expected. This is a UX bug rather than a functional one — navigation still works, but the close behavior is broken for overlays that use nested menus.
Ticket: #75925. Being actively tested.
What to do for now: If you’re running a Navigation Overlay with sub-menus and have mobile users, test this specific interaction. If it’s affecting your site’s navigation experience, a JavaScript workaround can be implemented as a temporary fix until the patch ships.
10. Decorative Images in Figure Elements Read Aloud by VoiceOver
Status: Open — still being tested as of March 2026
Decorative images placed inside <figure> elements are being picked up by VoiceOver (iOS/macOS screen reader) and read out as file names — which is incorrect accessibility behavior. Decorative images should be ignored by screen readers.
This matters for accessibility compliance. If you’re building sites that need to meet WCAG standards, this is worth tracking. The fix will require a core update — it’s not something you can work around cleanly without modifying individual image markup. We run regular WordPress accessibility checks for our clients; if this affects you, reach out.
What About WordPress 6.9.1?
WordPress 6.9.1 shipped February 3, 2026 with fixes for 49 bugs — split between 23 core tickets and 25 block editor issues. It addressed the email failures, the Adjacent Post Navigation infinite loop, classic theme rendering issues (partially), and a range of smaller editor inconsistencies.
If you’re still on 6.9.0, update to 6.9.1 first. It resolves a meaningful number of the issues on this list and was designated a “short-cycle maintenance release” — meaning the sole focus was stability, no new features.
A second maintenance release (6.9.2) may ship before WordPress 7.0 in April. Watch the Make WordPress Core blog if you’re tracking this closely.
Before WordPress 7.0 Ships (April 9, 2026)
WordPress 7.0 is scheduled for April 9, 2026 and is already in beta. The changes include the always-iframed post editor, viewport-based block visibility, and expanded AI tooling — all of which will introduce another round of plugin compatibility testing.
If the 6.9 experience taught anything, it’s that the smart move is to update plugins before updating core — not after. Plugin developers typically release compatibility updates in the days before or immediately after a major release. Updating core before your plugins are ready is where most of the pain comes from.
We manage updates for a number of our clients as part of ongoing care — staging first, plugin updates before core, rollback plan in place. If you’ve been updating manually and want a more reliable process before 7.0 hits, let’s talk.
Quick Reference: Fix Versions
| Issue | Status | Fix |
|---|---|---|
| WooCommerce checkout errors | Fixed | Update to WooCommerce 10.4.2+ |
| Yoast SEO meta box missing | Fixed | Update to Yoast SEO 26.6+ |
| Elementor visual conflicts | Fixed | Update to Elementor 3.24+ |
| Classic theme CSS breakage | Partial | Update to 6.9.1 + should_load_separate_core_block_assets filter |
| Membership/role plugin failures | Varies | Check plugin changelogs individually |
| Emails not sending | Fixed | Update to WordPress 6.9.1 |
| Adjacent Post Navigation loop | Fixed | Update to WordPress 6.9.1 |
| Classic editor styles in Site Editor preview | Open | Ticket #75779 |
| Navigation overlay back arrow (mobile) | Open | Ticket #75925 |
| Decorative images read by VoiceOver | Open | Ticket #75027 |
Dealing with a specific issue not on this list? Drop us a message and we’ll take a look. We keep a close eye on the WordPress ecosystem — it’s what we do.
