All plain html, nothing seems to be working

Everything was fine till I loggen in 2 hours ago and now it looks like everything’s broken. Any ideas why this might happen? The two attatched images are screenshoots from settings and all websites page inside piwik.

Try to load http://your_piwik_url/index.php?module=Proxy&action=getCss&cb=9463a31be42525a55bb478d2b4deedcf

delete browser cache and try again?