Clement Lefebvre has announced earlier today, September 17, 2013, that the main software repositories for the popular Linux Mint operating system will be closed for maintenance on September 18, 2013.
The maintenance process will start at 9 AM London, UK time and it will probably last until the next day, September 19, 2013.
All Linux Mint users are urged to remain calm during this maintenance. If you use Linux Mint 15 (Olivia) and you want to install or update some packages, go to Menu -> Preferences -> Software Sources, click the "Main (Olivia)" button from the "Mirrors" sub-section of the "Official repositories" section and wait a couple of minutes for the app to find another mirror.
Click the "Update cache" button when the new mirror has been added, and close the application. You will now be able to install packages on your Linux Mint 15 system. Users of older Linux Mint systems should follow these instructions.