[xwiki-users] accidentally deleted Main space, how to restore?

I'm a high school computer science teacher who's a recent immigrant from MoinMoin to XWiki. The subject says it all. I deleted my Main space accidentally and can't figure out how to restore everything. I've got the Main.WebHome page back, but I have three errors: Unknown macro: spaces Unknown macro: messageSender Unknown macro: activity How do I go about getting rid of these errors and restoring the content on the WebHome page? Thanks! Todd