Post editor errors out when Yoast is active on WP 6.8

[ajaykj]

Context and steps to reproduce

Opening the post editor displays an error. The content of the copy-error is

TypeError: Cannot read properties of null (reading 'toString')
    at pL (https://c0.wp.com/c/6.8/wp-includes/js/dist/components.min.js:33:143126)
    at n (https://c0.wp.com/c/6.8/wp-includes/js/dist/components.min.js:33:146597)
    at t.get (https://c0.wp.com/c/6.8/wp-includes/js/dist/components.min.js:33:146758)
    at t.render (https://c0.wp.com/c/6.8/wp-includes/js/dist/components.min.js:33:155778)
    at br (https://c0.wp.com/c/6.8/wp-includes/js/dist/vendor/react-dom.min.js:10:59368)
    at yr (https://c0.wp.com/c/6.8/wp-includes/js/dist/vendor/react-dom.min.js:10:59167)
    at Qs (https://c0.wp.com/c/6.8/wp-includes/js/dist/vendor/react-dom.min.js:10:121084)
    at wl (https://c0.wp.com/c/6.8/wp-includes/js/dist/vendor/react-dom.min.js:10:88341)
    at bl (https://c0.wp.com/c/6.8/wp-includes/js/dist/vendor/react-dom.min.js:10:88269)
    at yl (https://c0.wp.com/c/6.8/wp-includes/js/dist/vendor/react-dom.min.js:10:88132)

The site is on WP 6.8. The latest version of Yoast is active, and no other plugins (except Jetpack and Akismet) are active. There are no fatal errors or other issues. The site has no clear indications about the error unless the post editor is opened.

Site owner impact

Fewer than 20% of the total website/platform users

Severity

Major

What other impact(s) does this issue have?

No response

If a workaround is available, please outline it here.

Rolling back WP Core to 6.7.2 fixes the issue.

Platform

Atomic

Ref: p1744820229703649-slack-C03TY6J1A and p9F6qB-hB8-p2

[RafaelFunchal]

Just noting that we had two similar issues in the past:

• Bug: Post/Page Editor crashes when triggering Command Palette when a block is selected #81005
• The Editor shows TypeError: Cannot read properties of null (reading 'toString') when Gutenberg is active #97528

[mauropereiira]

We found another case discussed on this Slack Thread (p1744904859198669-slack-C03TY6J1A) related to the Theme theretailer.
We had to roll back WP to 6.7.2 to work.

[cat-og]

Another report here: 9672968-zd-a8c

Deactivating Yoast, Yoast Premium, and WPCode resolved the issue for the moment.

[namanhhe]

Another report: 9661767-zd-a8c

Deactivating Yoast, Yoast Premium, and SHE Media Infuse resolved the issue for now and brought the editing options back.

[nazilya06]

Another report: 9674680-zd-a8c

Conflict between Yoast SEO, Yoast SEO Premium, and Head, Footer and Post Injections plugins. Rolled back WP to 6.7.2.

[zdenys]

Wanted to note that depending on whether Gutenberg is active or not, the stack trace urls change a bit, but the underlying issue seems the same.

Aspect	Gutenberg plugin active	Gutenberg plugin off (or not present)
URL source	/wp-content/plugins/gutenberg/build/components/index.min.js	/wp-includes/js/dist/components.min.js
Error type	TypeError: Cannot read properties of null (reading 'toString')	Same
Stack trace	Different filenames/line numbers	Different filenames/line numbers

[ash1eygrace]

Related discussion: p1744964173931139-slack-C01SUGCAZQW

If anyone encounters this, if you can, please try to deactivate Page Optimize to rule out a possible conflict, and let us know your findings. Thanks!

[ahmadbaig1]

Same issue on 9669578-zd-a8c
Asked for a rollback to WP 6.7.2 for now.

[ezenisek]

I’ve spent many hours tracking down this issue and wanted to share my findings in case it helps others or aids in resolving the core conflict.

Environment:

WordPress Version: 6.8 (issue occurs), rolled back to 6.7.2 (issue resolved)

Theme: Tested with both custom theme and default Twenty Twenty-Four

Plugins:

Yoast SEO active

A few custom plugins, including:

One that injects scripts/styles into wp_head and wp_footer

One that dynamically manages block patterns or post metadata

One that syncs YouTube content and uses REST and admin JS

Symptoms:

The Gutenberg editor fails to load on posts and pages.

A blank screen appears when the window height exceeds a certain threshold.

DevTools open or resizing the window can temporarily fix or trigger the bug.

Console error:

Uncaught TypeError: Cannot read properties of null (reading 'clientHeight')
at t.value (editor-block.js?ver=3.97.0:2:4628)

No visible PHP errors or fatal logs; some deprecation notices but nothing crash-related.

Classic Editor works fine.

Private mode or disabling all plugins/themes did not resolve the issue.

Disabling Yoast alone didn’t fix it either — the issue persisted until WordPress Core was rolled back.

Additional Clues:

I initially suspected Spectra (UAGB blocks), but narrowed it down to a deeper Gutenberg issue, likely compounded by Yoast and DOM injections.

MutationObserver and ResizeObserver triggers were seen during window resizes, possibly causing reflows to break.

Scripts injected by custom plugins in the header/footer might be contributing to layout recalculation issues during Gutenberg's hydration/render cycle.

Resolution (Temporary):

Rolled WordPress Core back to 6.7.2 — everything works fine.

I’ve re-enabled all custom plugins and Yoast with no issues on 6.7.2.

Will monitor the thread and re-test on 6.8 once a patch or Yoast update is available.

[pauljacobson]

It looks like we have an instance of this issue in 9661767-zen

I have rolled WordPress back to 6.7.2 and asked the user to check whether they still experience this issue?

[ciampo]

From the error path:

• the issue is happening in the @wordpress/components package;
• it looks like some code is passing a null reference to some API from @wordpress/components that instead expects a defined reference to the dom.

I suggest loading a version of the editor where the Gutennerg plugin is built in development mode, which should hopefully give an error message that is easier to follow.

Also, I suggest testing one plugin / theme at the time to find the cause of the error

[Zurieee]

Is this related?
https://wordpress.org/support/topic/yoast-is-removing-custom-elementor-css

[dragstor]

Another case in 9698484-zen