We are sorry to announce that starting with February 4, 2016, Canonical will stop “feeding” its Ubuntu 15.04 operating system with security/critical fixes and software updates. Those of you who still use the Vivid Vervet release must upgrade to the Ubuntu 15.10 (Wily Werewolf) operating system as soon as possible, following the instructions provided at https://help.ubuntu.com/community/WilyUpgrades.