Hello Dank Fur Die Hilfe,
Please try to follow the tutorial: http://www.venustheme.com/how-to-install-sample-data-after-magento-installation-a-video-guide/
Just create tempcp (theme settings item in venustheme > ves template panel > theme control panel). Then run import data sample.
If you can not do it. Please send me the site information into private message or to email: [email protected]