🇦🇹Austria @limas

It seems to be ckeditor5 (list_start_reversed). No error when ckeditor5 is disabled.

Using drush to update db:

...
[notice] Update started: ckeditor5_post_update_list_start_reversed
>  [error]  Error: Call to a member function getConfigDependencyName() on null in Drupal\editor\Entity\Editor->calculateDependencies() (line 122 of /core/modules/editor/src/Entity/Editor.php) #0 /core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php(321): Drupal\editor\Entity\Editor->calculateDependencies()
...