'Add this news' and 'Add this albums' buttons connect to strange screens

I type a new page name in text field then click on 'Add this news' button. It shows and edit form but there's no edit field.
Only if I click on 'Cancel' button it shows "This document does not exist in this Wiki.
You can click on "Edit this Page" to create it"
Or if I click on 'Preview' or ''Save button it shows a screen with content: "Enter your title here
The content appears on the article page. The extract will appear on the home and category pages. If there is no extract the first 400 caracters of the content are used instead."
The same thing happens when I create a new albums