Magento site dissapeared :( pls help

[tofriede]

Hi, we updated the copyright date in the configuration/design/footer section. After pressing the "save configurations"-button everything dissapered. The site is no longer accessible under the domain. Also cant login anymore into the magento-backend. I already did some research and checked the web/unsecure/base/url and web/secure/base/url in core_config_data. The values are both still correct. Pls help me. Thanks in advance. My website is http://www.cosmetic-shop-online.de/