'The requested URL could not be retrieved' or 'Internet Explorer cannot display the webpage'

You may get this message due to:

Network

The screen below was produced when attempting to surf the web after adding a network, but the network wasn't saved properly on exiting Appliance Manager. The solution was to add the network again, save it, verify it was saved, then surf the web again. The problem is reflected by the first bullet (highlighted below) which basically says your machine IP is unknown to iPrism.

HTTPS

Because of encryption, Proxy mode will indicate a blocked HTTPS site with a page similar to the following:

How do I Establish an Authenticated Web Session for HTTPS?

 

If you are using Internet Explorer 8, transparent (bridge) mode will indicate a blocked HTTPS site with a page similar to the following: