When accessing Facebook, messages such as Facebook transfer data and Facebook pending can be seen in the internet browser window with b.static.ak.fbcdn.net. Facebook b.static.ak.fbcdn.net should not be misunderstood as an error message. Facebook b.static.ak.fbcdn.net are Facebook servers that provide content to the browser such as images. They also provide real time information about chat sessions, services or notifications. An open web page on Facebook always scans for messages and alerts that can be obtained from the Facebook b.static.ak.fbcdn.net servers. These messages will always appear on the open browser window and will pose no problem for the user at all.
When you're on Facebook, the browser's status bar consistently displays one of the following messages:
Transfer data from b.static.ak.fbcdn.net
*.static.ak.fbcdn.net servers are actually Facebook servers. They are responsible for providing static content site (photos, videos, pictures, etc.) as well as information in real time like chat services or notifications.
Therefore, when a page is open on Facebook, it is constantly looking for new alerts for you to view, so the message remains permanently.