A recent change in Google Earth changes the way links are processed for content inside a feature balloon to make previously unspecified behavior more clear. As a result, clicking a link from within a KMZ that has an invalid link structure will take users to a page stating “The link that sent you here may be formatted incorrectly. Click on the link below to try using legacy mode.” If you see this message, you should change the structure of your KML/KMZ content to ensure full compatibility with future versions of Google earth. See this article for more information, including details on how to appropriately restructure your KMZ content.