The animated tutorials run by accessing the java viewlets from Mindjet.com. They use a .vbs skin file that may be perceived as a potentially hostile file by some firewalls and security measures. The "incorrect skin" error occurs when the .vbs files are blocked.

As a possible solution, you can try downloading the viewlets supplemental pack (located at support--software downloads) and running locally from your machine.

You can also try lowering your security settings on your browser or firewall. Most likely you will need to contact your administrator for this option.