LENOVO LAPTOP QUESTION?

I have a new Lenovo G460/G560 I'm used to. QUESTION: What does it mean when you click on a link, even something simple like Stationery in email, and you get ? Yellow starburst with a red exclamation mark AND you're not allowed to access the site? If you can find the answer in the manual, just give me the page number, please. My eyesight is not great...