Import a static template

To add the static template (which helps to render the page) choose the menu Template at the left side, click on the page Root Page Museum and then click on Edit the whole template record. Now go to the tab Includes,search for the title Include static (from extensions) and click on the entry CSS Styled Content TYPO3 v.4.2 (or higher).

Clear the Cache, you should see now the content in the Browser.