Hello,
Try these Steps:
1) Run upgrade.bat from C:\Program Files\Symantec\Symantec Endpoint Protection Manager\bin
2) Run the Management Configuration Wizard for SEPM
If an installation package has been unexpectedly deleted from the SEPM, the package may be added back into SEPM via launching the SEPM console --> admin --> Install Packages --> Add client install package --> point to the the installation media for SEPM: Symantec_Endpoint_Protection_12.1_Full_EN\SEPM\Packages\<SAV32 or SAV64>.info file. This will restore the installation package of your choosing.
If the above, does not help please work on the Disaster recovery steps for SEP 12.1
http://www.symantec.com/docs/TECH160736
Hope this helps!!!