Silverlight seems not to be installed on your machine. You can
browse Maps without Silverlight here
install Microsoft Silverlight Plugin.
Holen Sie sich Microsoft Silverlight

Please note:
Silverlight is not supported anymore by modern browsers such as Chrome.
You may still use this Silverlight-map-interface by
installing an older Google Chrome version (e.g. available here),
or by accessing this webpage using a portable version of Chrome.