Error in post category settings

Also in SEO Tools I get:

ReferenceError: Can’t find variable: yoastWebpackJsonp
https://www.aktueltspania.net/wordpress/wp-content/plugins/wordpress-seo/js/dist/analysis-830.min.js?ver=8.3-b-modified-1538256346 line 1
TypeError: undefined is not an object (evaluating ‘window.yoast.analysis’)
https://www.aktueltspania.net/wordpress/wp-content/plugins/wordpress-seo/js/dist/wp-seo-recalculate-830.min.js?ver=8.3-b-modified-1538256346 line 1
TypeError: undefined is not an object (evaluating ‘j.string.wordBoundaries’)
https://www.aktueltspania.net/wordpress/wp-content/plugins/wordpress-seo/js/dist/components-830.min.js?ver=8.3-b-modified-1538256346 line 42

Can you confirm you are using WP 4.9.8 and Yoast SEO for WordPress 8.3?

It might be a plugin or theme conflict. Can you try and gather as much information for us as possible? Please perform the following:

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.

Disabling Yoast makes this error in category settings disappear:

TypeError: undefined is not an object (evaluating ‘e.data.indexOf’)
https://www.aktueltspania.net/wordpress/wp-content/plugins/wordpress-seo/js/dist/wp-seo-quick-edit-handler-830.min.js?ver=8.3-b-modified-1538256346 line 1

Disabling all other plugins than Yoast and using 2017 theme produces these errors in Yoast SEO tools:

ReferenceError: Can’t find variable: yoastWebpackJsonp
https://www.aktueltspania.net/wordpress/wp-content/plugins/wordpress-seo/js/dist/analysis-830.min.js?ver=8.3-b-modified-1538256346 line 1

TypeError: undefined is not an object (evaluating ‘window.yoast.analysis’)
https://www.aktueltspania.net/wordpress/wp-content/plugins/wordpress-seo/js/dist/wp-seo-recalculate-830.min.js?ver=8.3-b-modified-1538256346 line 1

TypeError: undefined is not an object (evaluating ‘j.string.wordBoundaries’)
https://www.aktueltspania.net/wordpress/wp-content/plugins/wordpress-seo/js/dist/components-830.min.js?ver=8.3-b-modified-1538256346 line 42

If you’re getting errors with Yoast SEO for WordPress v8.4 and a default theme like TwentySeventeen both enabled, and all of your other non-Yoast plugins deactivated, based on the information you provided, we expect this to be a bug. We’re actively using the bug tracking on our GitHub repository so your best next step would be to create a new issue for our developers at https://github.com/Yoast/wordpress-seo/issues/new. You will need an account to create a new issue. If this is your first bug report, please check out: https://kb.yoast.com/kb/how-to-write-a-good-bug-report/.

Don’t forget to include the URL to this conversation in your bug report.

No further response, closing.