Suddenly I've noticed something weird on my Wordpress website. When I'm logged in, the wp-admin bar isn't visible anymore. And then I wanted to change the copy of a post and my console throws a massive amount of errors:

Also the featured image box keeps loading. It seems that the image won't load.

I haven't changed anything on the code of the website and no extra plugins installed. I've already disabled all the plugins and changed to the default WP theme. But the errors are still there.

I don't have this problem locally.

I've did some more tests and installed the classic editor plugin. I don't see any errors in the admin right now. So it feels that the issue is caused by Gutenberg editor.