Solution # 00007725
Scope: Any Barracuda Product on any firmware version that blocks webpages.
As the internet has grown, websites have increased in size from one or two pages with simple static content, to pages involving dynamic content sourced from several locations. In an effort to speed up page loading times, some website operators (e.g. Google, Dropbox, etc) have made the decision to locate static content like images, (logos, backgrounds, other UI elements) scripts, et cetra on different domains from their main site (for example: dropboxstatic.com, or gstatic.com). Unfortunately, this means that these "secondary" sites will also have to be white listed in order to have those pages properly displayed.
Some providers are kind enough to provide a list to the domains that they use. Dropbox is one of these: https://www.dropbox.com/en/help/217.
An alternative to white listing all of these sites is to use the Content Filter rules to permit access to these sites.