Failed to execute ‘postMessage’ (readability in wp-admin now showing)

I have the same Error on:

WP: 4.9.8
Yoast Version 8.1.2

this bug crash the gutenberg editor with “Updating failed” messages.

@wbrnd if you have an active subscription of Yoast SEO Premium, please feel free to reach out to us at [email protected] directly in order to get email support.

It’s possible that there is a plugin or theme conflict which could be causing these issues — https://kb.yoast.com/kb/how-to-check-for-plugin-conflicts

@mikes41720 I’m with the same error

Yoast Version: 8.1.2
Wordpress: 4.9.8

wp-seo-analysis-worker-812.min.js:13 Uncaught (in promise) DOMException: Failed to execute ‘postMessage’ on ‘DedicatedWorkerGlobalScope’: TypeError: Cannot read property ‘addAssessment’ of null could not be cloned.
at a.value (https://estudionoob.com.br/nb-plugins/wordpress-seo/js/dist/wp-seo-analysis-worker-812.min.js:13:201377)
at a.value (https://estudionoob.com.br/nb-plugins/wordpress-seo/js/dist/wp-seo-analysis-worker-812.min.js:13:205641)
at a.<anonymous> (https://estudionoob.com.br/nb-plugins/wordpress-seo/js/dist/wp-seo-analysis-worker-812.min.js:13:1334607)
at i (https://estudionoob.com.br/nb-plugins/wordpress-seo/js/dist/wp-seo-analysis-worker-812.min.js:13:190529)
at Generator._invoke (https://estudionoob.com.br/nb-plugins/wordpress-seo/js/dist/wp-seo-analysis-worker-812.min.js:13:191649)
at Generator.a.(anonymous function) [as next] (https://estudionoob.com.br/nb-plugins/wordpress-seo/js/dist/wp-seo-analysis-worker-812.min.js:13:190708)
at s (https://estudionoob.com.br/nb-plugins/wordpress-seo/js/dist/wp-seo-analysis-worker-812.min.js:13:1332660)
wp-seo-analysis-worker-812.min.js:13 Uncaught (in promise) DataCloneError: Failed to execute ‘postMessage’ on ‘DedicatedWorkerGlobalScope’: TypeError: Cannot read property ‘addAssessment’ of null could not be cloned.

• This reply was modified 6 years, 2 months ago by Samuel.

@martdsam @wpuser34444 Can you please confirm you are using the most recent Yoast v8.2? You can learn more about updating here: https://kb.yoast.com/kb/how-can-i-update-my-free-plugin/

If you are still receiving the error after confirming you are upgraded to version 8.2, can you then perform a conflict check and let us know what the results are? We have more information on this here: https://kb.yoast.com/kb/how-to-check-for-plugin-conflicts

@devnihil Here is ok now. Thank you ??

no, new error with: 8.2:

commons-820.min.js:1 Uncaught Error: only one instance of babel-polyfill is allowed
at Object.<anonymous> (commons-820.min.js:1)
at Object.<anonymous> (commons-820.min.js:1)
at e (commons-820.min.js:1)
at Object.<anonymous> (commons-820.min.js:6)
at e (commons-820.min.js:1)
at commons-820.min.js:1
at commons-820.min.js:1

Cant save any page

@wpuser34444

can you confirm this issue is occurring with Yoast SEO for WordPress 8.2 and the latest version of Gutenberg, with all of your other plugins deactivated, and only using a default theme such as TwentySeventeen?

1. Make sure the issue doesn’t persist when Yoast SEO is disabled.
2. Check for conflicts.
3. Check for JavaScript errors with your console.

If you find any JavaScript errors related to Yoast SEO or if there is a conflict with a plugin or a theme, you can create a new GitHub issue for our developers. Please report the issue to a third party developer as well.

If you didn’t find any conflicts or errors, we think the issue is specific to your site. We’d need to investigate further but are unable to do so on these forums. You can purchase Yoast SEO Premium and receive our Premium email support and we can help you further.

@mikes41720 also I can confirm that the issue was gone after updating to version 8.2. Thanks for the support!

Thank you for the update @wbrnd! We are glad to know that the issue is now resolved.