When using some Windows operating systems and Internet Explorer to view 3D content created in Live 3D, you may get a security warning: a yellow Information Bar may appear at the top of the browser window that says:
"To help protect your security, Internet Explorer has restricted this file from showing active content that could access your computer. Click here for options..."
You have to click the bar, choose "Allow Blocked Content..." and then click "Yes" to the security warning.
This behavior can be disabled in the Internet Explorer Tools menu. For more information, see Microsoft Knowlege base article 883255