the news-item does not install itself fully automatically, when news is called (maybe it should in the future). do the following
- type in: .../xowiki/news-item
- type in: .../xowiki/news
alternatively, you could do in the first step xowiki/?import_prototype_page=news-item
explanation: "news" uses two prototype pages, "news" and "news-item". "news" is the summary page, "news-item" is the form to add and update news entries.
hope, this helps.