It looks like something went wrong when we tried to load the Real-Time SEO content analysis library. Please check it the module is installed correctly.

I have the same issues on Drupal 9.5.9 and yoast_seo 8.x-2.0-alpha9

Also in the browser console I can see error like:

- GET https://x.ddev.site/libraries/rtseo.js/dist/rtseo.min.css?r43df
- The resource from “https://x.ddev.site/libraries/rtseo.js/dist/rtseo.min.css?r43df” was blocked due to MIME type (“text/html”) mismatch (X-Content-Type-Options: nosniff).
...

I fixed this issue for my project via updates in `composer.json` file.

I added "installer-paths" for libraries:

...
"web/libraries/{$name}": [
  "type:bower-asset",
  "type:npm-asset",
  "type:drupal-library"
]
..

and re-install `yoast_seo` module via composer.

Details here https://www.drupal.org/docs/develop/using-composer/manage-dependencies#t... →

These requirements for correct configurations in composer.json files will probably need to be specified somewhere in the Readme/Module description.

That looks helpful, @azovsky. I'll try it.

Thanks very much.