Library not accessable/visible anymore

Hello,
I am having a major problem as I work on a site for a client.
Without having done anything and haven’t worked on the site for a few days my library is not visible or accessable anymore…
Furthermore is the slider on the homepage and any further information below the slider that I created under the HOME button in the “Theme appearance” not there anymore. You just see the navigation bar of the page. Please have a look on http://www.atanda.com.au to see what I mean.

I use the Theme Corpo and installed the Corpo Toolkit to aktivate the slider. Once I deactivate the Toolkit the copy of the homepage appears again, but the library is still not visible.

What could have happened to the site and what can I do??

Thanks a lot for any help!!!