Board Thread:Support Requests - Designing Your Wikia/@comment-28068238-20160407152823/@comment-5558012-20160407154323

Click the "Edit" button on the article, you aren't using the new VisualEditor (based on the article's history) so on the right side of the edit page you should see a section called "Categories" (if you don't see it you need to uncollapse the side rail by clicking the arrow on the right side of the edit space). In this section, hover over the category and you should see a little trashcan icon appear to the right of the category name. Click it, the category will be deleted, and you can save the page.