Please excuse, I recall my request. I changed the top margin of list elements, that's why they disappeared.

when I call my the page Main/AllDocs I used to have a tab to view my documents in a tree. All tabs disappeard (also the "deleted pages", "deleted attachments" etc.). Is this a commonly known bug? How can I redisplay this (as the tree is a necessary tool to keep an overview of the wiki's structure and contents)?