Please rebuild the categories on the newly reopened nl.wikinews. After importing from Incubator, they are not yet up-to-date (cf. https://incubator.wikimedia.org/wiki/Category:Wn/nl/3_juli_2017 vs. https://nl.wikinews.org/wiki/Categorie:3_juli_2017).
This can be done by running refreshLinks.php.