3D City shows a white screen and doesn't load

Solution:

This problem is caused because of the security settings of your browser. In order to get 3D City running you should

do the following:

Open the Internet Options submenu of your browser as it is shown on the following screen shot:

Go to "Security" tab and click on "Custom level" button:

Will be opened a "Security Settings" window in which you should make the following settings (marked with blue):

And also, if you are on Windows Vista, disable the Protected Mode of the browser. Then 3D City will work fine.