[xwiki-users] I deleted a document, and now a whole space is missing, and etc.

I deleted a document from a space, and that space is now missing. Another intersting thing is that when I visit a document index, I see The "documents" macro is not in the list of registered macros. Verify the spelling or contact your administrator. I said to myself, "Oh my god, somebody help me. I'm losing my data!!!" What is going on?