Hello,
This usually happens with the users carrying the Symantec Protection Suite.
In case you do not see the Symantec Endpoint Protection 12.1 RU3 version on Symantec Flexnetoperations (earlier Symantec Fileconnect), you may see the same in coming few days.
However, incase you need it very urgently, you may contact the Symantec Licensing Department.
They can help you with a Temporary License Number.
Website: http://symantec.custhelp.com
Phone number: 1-800-721-3934
Email: license@symantec.com
Hope that helps!!