From time to time, we perform server maintenance and upgrades on particular servers. It's possible that the file you are trying to download is hosted on a server which is currently offline, while maintenance is being performed.
In this case, you will see the error message:
The server hosting this file is temporarily unavailable due to system maintenance. Please try again shortly.
Rest assured, if you see this error, our team are aware of the problem, and are working hard to restore the service.
For more information, you can check the status of individual servers here: