Starting December 14, the Mac OS X Mountain Lion (10.8) operating system will no longer be supported by Apple and therefore, will no longer receive security updates. Fermilab-owned computers, by laboratory policy, must run vendor-supported operating systems to avoid security risks. Mac OS X Mountain Lion users must submit a Service Desk ticket at https://fermi.service-now.com/fsc/ to have their computer upgraded to OS X Yosemite (10.10) before December 14. After that date, any computer running OS X Mountain Lion will be blocked from accessing the Fermilab network. If you have any questions, please contact the Service Desk.